Probable Causation

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Episode 36: Ellora Derenoncourt

Jennifer Doleac

Ellora Derenoncourt

Ellora Derenoncourt is an Assistant Professor of Economics and Public Policy at the University of California - Berkeley.

Date: September 15, 2020

Bonus segment on Professor Derenoncourt’s career path and life as a researcher.

A transcript of this episode is available here.

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Episode Details:

In this episode, we discuss Prof. Derenoncourt's work on the Great Migration and income inequality:

"Can you move to opportunity? Evidence from the Great Migration" by Ellora Derenoncourt.

OTHER RESEARCH WE DISCUSS IN THIS EPISODE:

Transcript of this episode:

 

Jennifer [00:00:08] Hello and welcome to Probable Causation, a show about law, economics and crime. I'm your host, Jennifer Doleac of Texas A&M University, where I'm an Economics Professor and the Director of the Justice Tech Lab.

 

Jennifer [00:00:19] My guest this week Ellora Derenoncourt. Ellora is just wrapping up a postdoc at Princeton University, and she'll be joining UC Berkeley's Economics Department and Goldman School of Public Policy as an Assistant Professor in the fall. Welcome to the show.

 

Ellora [00:00:33] Thanks so much for having me.

 

Jennifer [00:00:35] So today we're going to talk about your research on the Great Migration in the United States during the mid 20th century and how it affected economic mobility as well as local spending on things like policing and incarceration. But to kick things off, could you tell us about your research expertize and how you became interested in this topic?

 

Ellora [00:00:54] Sure. So I'm an Economic Historian and a Labor Economist. And because of that background and training as an Economic Historian, I remember the moment that I saw these maps published in The New York Times of - you know, where is the land of opportunity in America? Some of the work coming out of Raj Chetty's team and his collaborators. And I remember noticing right away that in these maps of the variation in upward mobility across the United States, you had one the South as this concentrated region of low upward mobility. But then these pockets in the north and west of the country, in urban areas that were also pockets of very low upward mobility. And I looked at those spots and I thought, wait a minute, those are the Great Migration destinations. Those were the cities that, you know, millions of African-Americans migrated to in search of better opportunity in the - you know, over the course of the 20th century. That's tragic that today they look to be very poor places for families to actually raise their kids. So I was motivated to understand what happened, what could explain this kind of tragic reversal of fortune.

 

Jennifer [00:02:16] Your paper is titled "Can you move to opportunity? Evidence from the Great Migration." So let's back up and start with some history. What was the Great Migration?

 

Ellora [00:02:26] Sure, absolutely. The Great Migration was what I sometimes call the largest natural experiment in moving to opportunity in US history. It was a - an internal migration of approximately six million African-Americans out of about 14 states in the US south into cities in the north and west of the country. So places like Detroit, Chicago, Baltimore, in their heyday in the early to mid 20th century.

 

Ellora [00:02:59] So the migration was prompted by multiple forces, some having to do with kind of demand-side or pull factors and others having to do with push factors from the origin. Among the kind of pull factors, the early 20th century was a time where industrial production was ramping up, especially during World War I and World War II. And there were labor shortages relating to the closure of our borders and big reductions in European immigration into the US. So that opened up demand for black workers from the south - this sort of lower wage pool of labor for the first time really in a - an expanded way.

 

Ellora [00:03:48] At the same time, on the flip side, in the South, black families were concentrated in agriculture and farming, and that sector was undergoing mechanization and job loss during the mid 20th century and early 20th century. And black families had been facing a regime of Jim Crow in the south and severe restrictions on their political, social, and economic rights. So that was just the kind of flammable combination that meant it didn't take much more to spur massive outmigration from the region. But what that outmigration did and what it entailed on the receiving end in those cities in the north and west of the country was a dramatic change in their racial composition. And so that's the kind of shock that I study - to see how did those cities transform in response to this shock.

 

Jennifer [00:04:39] So before this paper, what did we know about the ability to move to opportunity broadly and about the impacts of the Great Migration in particular?

 

Ellora [00:04:48] So there are two kind of strands of literature that this paper fits into in exactly those two areas. First, the work of Raj Chetty, Nathan Hendren, Maggie Jones, and their collaborators found that there's a great deal of heterogeneity in intergenerational mobility by race and gender across the United States. And the work of Raj Chetty and his collaborators prior to this as well showed that locations seem to have long run effects -  causal effects on kids, adult outcomes. And so they've provided a lot of evidence of these local statistics on upward mobility, their variation, and some of the causal factors.

 

Ellora [00:05:36] But where I see my paper fitting in is to ask the question, well, how stable are these neighborhood effects - these causal effects of place? It's not so much the soil or the air that makes a place good for families, but rather what I end up finding is that it's really the behavior of local residents and local governments that help determine opportunities in locations.

 

Ellora [00:06:03] Now, from the perspective of the Great Migration literature, prior work has focused on the contemporaneous effects of the Great Migration. So, for example, Boustan, in a series of papers and a book, documented the labor market effects of black migrants arriving from the south and found that competition for black incumbent workers in the north increased. And that slowed racial wage convergence in the north, actually. At the same time, she looks at how the Great Migration affected residential sorting patterns and white flight in the mid-century. Now, where I see this paper carrying that literature forward is no one had really asked, well, how do these locations that were part of the kind of mythos in African-American history as the promised land, a place - places where African-Americans could aspire to parity with white Americans - how are they today for the descendants? I would say there's great - a great deal of consensus that the wage gains for the migrants themselves in the 20th century were enormous. You could roughly double your earnings as a black migrant going from south to north.

 

Ellora [00:07:19] But what I find is that a couple of generations later, that ladder of opportunity has been removed or stripped away. And today there's really no more kind of arbitrage opportunity. Black children growing up in the south face as good chances in terms of their income as adults, as those growing up in the north. And that's a remarkable convergence between the regions over the last 70 years.

 

Jennifer [00:07:46] Yeah. So as you say, you're interested in the intergenerational effects here. So that is what happens to not just the people who moved, but their children and grandchildren. So as we think about potential mechanisms, what are the various channels through which we might expect a move to the north in the mid-1900s to affect the economic outcomes of subsequent generations?

 

Ellora [00:08:06] So the key mechanisms - there are a couple of potential stories one could tell, and I was very keen to distinguish between those stories. One, of course, a migration event is going to change the composition of people living in the location. So you could imagine a situation where families move from the south and those families are selected in a particular way, meaning they're less able to secure good outcomes for their kids and for future generations. That kind of selection story could explain why Great Migration cities today, generations down the line, don't look as good. But it would be merely driven by the composition of the families in those locations today.

 

Ellora [00:08:53] That's not what I'm going to find is the mechanism here. Instead, what I find is that the Great Migration induced changes in the places themselves - in local institutions and persistent changes in residential behavior that have long run effects down the line. And the two sort of smoking guns, in terms of the mechanisms that I'm going to find, one is the behavior of white incumbent households at the time that migrants were moving in in such large numbers. I find that white households moved away from shared urban neighborhoods and also moved their kids out of the public school system at higher rates and into private schools.

 

Ellora [00:09:38] The second sort of smoking gun that I find is that the quality of the urban environment in these destination locations really sharply declined starting around 1960. And what I mean by that, in terms of the quality of the urban environment, I observed that Great Migration locations have higher urban murder rates. I also find that economic activity is more dispersed with higher commute times. And I find that local governments, in terms of public policy investments over this period, really shifted investments towards police as opposed to, you might imagine, them increasing investments in education or health and sanitation given this inflow of poorer people from the south. But that's not what I observed. And instead, I see this investment in police and probably as a result of this higher rates of incarceration in these locations and that - those effects actually persist for decades, so through the 2000s, these areas really look different in terms of their public investments and incarceration rates.

 

Jennifer [00:10:48] I have one more background question on context before we get into your empirical strategy. So how did black southerners decide where to move within the north?

 

Ellora [00:10:57] So if you look at the history and what's been written about the Great Migration and other papers in economics which have studied this moment, one of the most important predictors of where people moved was where people in their community had moved before. So there's a very nice paper by Evan Taylor and Bryan Stuart, where they can really trace - they look at Beloit, Wisconsin, and really find this strong connection in the first wave of the Great Migration between those who had moved from a very particular county in Mississippi and arrived in Beloit that created a kind of chain reaction of people continuing to migrate from that community.

 

Ellora [00:11:45] Of course, you know this - as I mentioned before, one of the important factors was labor demand. So places that had booming industry were attractive destinations for black migrants from the south. Isabel Wilkerson in her book "The Warmth of Other Suns," excerpts from a survey that was administered to black southerners arriving in Chicago in the 19-teens. And all of them, or rather most of them, mention better wages and better living conditions as the main impetus for moving. So clearly, jobs were a very important factor for black migrants in terms of deciding where to go. So the industrial demand was a big - was an important pull factor, but one that I'm going to try to disentangle from the push factors that were kind of sending migrants out.

 

Jennifer [00:12:40] Okay, so as you began thinking about this project and you've got these various pull and push factors that you're thinking about and reading about in the literature, what were the main challenges you had to overcome in order to measure the causal effects of the Great Migration? Is it mostly a data challenge or mostly an identification challenge, or is it really both?

 

Ellora [00:13:00] It's probably really both, but maybe any researcher would say that. So in this case, you know, the first thing to acknowledge is that Great Migration destinations were not randomly chosen. Instead, as we've just discussed, there were specific features of destinations that made them attractive at that time, for example, the prevalence of jobs in industry. But you might worry then that characteristics of these destinations both drew migrants in and independently had an effect on upward mobility down the line. So probably the most salient example or story would be that Great Migration migrants were drawn to the major industrial centers - you can think of again, Baltimore, Detroit, et cetera. Those places then undergo deindustrialization, which we know, you know, is correlated with low upward mobility today. So from that perspective, one major confounder would be deindustrialization in this story of trying to understand the long run effects of the Great Migration on the destinations. So that was the first sort of thing to try to disentangle is how do I make sure I'm picking up this racial composition shock and its effect on destinations as opposed to predictors or correlates of black migration to those locations that might have independent effects on upward mobility down the line.

 

Jennifer [00:14:34] So as you're describing - a primary challenge here to measuring the causal effects of black families moving to particular places in the north is where they chose to move isn't random. So, for instance, they might have deliberately moved to places that offered particularly good opportunities for themselves or their children. And so a simple comparison of outcomes across communities would give us a biased estimate of the effect of this influx of people. So your empirical strategy overcomes this problem. You create a variable that uses what we would think of as the good or random variation where people settled due to luck or external forces and separates it from what we'd consider the bad variation due to deliberate choices of the people who moved. So that good variation gives you a natural experiment that allows you to measure the causal effect of the Great Migration. So walk us through your approach here.

 

Ellora [00:15:24] Absolutely. So what I'm going to do is use what's known as a shift-share or Bartik style instrument to study the causal effect the migration had on destinations. Now, this instrument has been used many times, first and foremost, to study the labor market effects of immigration into cities. But it was also first applied to the context of the Great Migration by Boustan 2010. And the key ingredients and the most important intuitive sources of variation are twofold. One variation in the location choices in my context of pre 1940 black southern migrants. And two variation in outmigration across counties within the south over the course of the migration. Now I'm focused on the second wave of the Great Migration from 1940 to 1970, which was also the largest wave with over four million people moving during that time.

 

Ellora [00:16:29] And in order to construct this instrument, what I'm going to have to do is make use of the 1940 complete count US census, which has been declassified since 2012. So before that researchers couldn't access individual level data from the historical census out of concerns for privacy. But after declassification, we get information on the universe of enumerated individuals, which is roughly 132 million people for 1940. Now what I can do with that is utilize the responses to a question the census actually began asking only in 1940. It was a question about where did you reside five years ago? And the reason the census started asking it is because they wanted to understand internal mobility during the Great Depression. Now, what's very useful about this is I can identify every black individual in 1940 who lists a southern county of residence as their place that they lived in 1935. What that means is that I can construct for every southern county, the distribution of black individuals who listed that county as their county residents in 1935 but reside in a northern city - and by northern here, I simply mean non-southern - non-southern city by 1940. So that allows me to measure directly the kind of idiosyncratic settlement patterns of black migrants prior to 1940.

 

Ellora [00:18:07] What I'm then going to do is interact those settlement patterns with variation and outmigration from their origin counties over the 1940 to 1970 period, but relying specifically on southern economic variation in outmigration. Now what I mean by that is you have for example - you know and I can use the case of Detroit and Baltimore, both major Great Migration destinations, but the two cities differ dramatically in where black migrants from the south had actually come from originally. So Detroit drew the plurality of its migrants from Alabama, while Baltimore drew the plurality from Virginia. Now, Alabama was a cotton planting state and underwent significant job loss in that sector over this period due to mechanization. And it saw a ton of outmigration over this period. By contrast, Virginia was a state that actually received a substantial number of defense contracts during World War II to build for the war. That actually retained migrants and kept jobs there. So, Virginia - if you look, actually had much lower levels of outmigration over this period. So that's exactly the kind of variation that comes from southern economic conditions or push factors that I want to use to generate a shock to Detroit and Baltimore. So I'm going to interact those pre 1940 settlement patterns with post 1940 shocks to the origin locations in the south to generate a predicted inflow of black migrants into cities like Chicago, Detroit, Baltimore, et cetera.

 

Jennifer [00:19:56] So folks might be getting a sense of - from your description of the census, a major piece of this project was pulling together data from a variety of sources. It's amazing to read through the paper and just see how much work clearly went into this. So tell us about all the various data sets you wound up using in the study and how you put it all together.

 

Ellora [00:20:17] Right. Yeah, a lot of blood, sweat, and tears went into this process. So first there are the historical censuses. I've talked a lot about the 1940 census. It was critical for constructing this instrument. It was also critical for painting a picture of upward mobility across different locations in the US in historical period and for different race and gender groups. Because I want to understand, you know, how did mobility change in these locations, not just, you know, how do they compare today? So I use not just the 1940 census, but the earlier historical censuses all the way back to 1920. And those allowed me to construct upward mobility statistics for black teenagers while they were still co-residing with their parents. And the reason one has to resort to these educational mobility measures is that measuring income intergenerational mobility historically would require linking individuals across censuses. So you get one observation of them as kids and you can observe their parents, but then you need to link across to another census to observe those individuals once they've become adults. The problem with linking African-Americans across censuses is that a key input into historical linking procedures is uniqueness of both first and last name. And African-Americans have fewer unique surnames as a direct legacy of slavery. So matching methods typically work poorly for African-Americans. So that's the first piece. These educational upward mobility statistics from 1920 to 1940.

 

Ellora [00:21:57] I then combine all of this information with contemporary mobility statistics. Now those have been made publicly available by Raj Chetty and his collaborators through the Opportunity Insights website. So that's a fantastic resource. But then as I mentioned, I wanted to understand how did Great Migration locations changed? So I kind of had to ask myself, well, what are all the possible relevant ways that they might change. And for trying to understand the environment for kids, I was interested in residential patterns, in schooling patterns, and in local government expenditures and investments. So that required pulling data together from - for the latter, the census of state and local governments, which has been conducted in a very consistent form back to 1932. But the data aren't in the easiest format to use before roughly 1967. So I digitized the census of state and local governments from 1932. I did - ended up digitizing different reports from the US Census in 1960, for example, correctional facilities, populations by race, by county. And I used historical reports on crime, for example, uniform crime reports that also date back to the 1930s. So there was a lot of pulling together statistics from different ports which were often in PDF format, and so that required digitizing. And then the second big step was really harmonizing these different statistics over time. In the end, I end up with a database of characteristics about Great Migration locations from roughly 1920 to 2015, so almost 100 years of data.

 

Jennifer [00:23:56] And what is the outcome variable you're focused on in your main analysis - measuring economic mobility?

 

Ellora [00:24:02] The main outcome variable I'm focused on is an - a measure of adult income for children conditional on their parents economic status. So the measure I used specifically is average income rank for individuals from specific points in the parent income distribution. And I focus primarily on the 25th percentile of the parent income distribution because we really think about that as capturing some measure of absolute upward mobility for individuals who grew up in low income families.

 

Jennifer [00:24:38] Okay, let's talk about the results. What do you find is the effect of the Great Migration on upward mobility in northern cities?

 

Ellora [00:24:45] So first and foremost, I find that growing up in a Great Migration city today lowers children's long run outcomes, and specifically for individuals growing up in low income households, a one standard deviation larger historical black migration into your childhood commuting zone is associated with a 12% reduction in household income. And here I'm speaking just for children on average, not distinguishing between black and white kids, which I will in a second. But the first thing to say right away is - I mentioned before you could tell a story where selection explains these results. The families that live in Great Migration locations today are potentially negatively selected in terms of ensuring good outcomes for their kids. So if they happen to be concentrated in these Great Migration locations - you know, even if I have at this point isolated exogenous variation in being a Great Migration destination, then this might explain the results.

 

Ellora [00:25:51] But that's not at all what I find. What I find instead is that the mechanism - the channel is a change in the childhood environment, in the location itself. So I'm happy to explain how I - how I did that. And I'll get into more details on that in a second. But I just want to highlight the next kind of key result, which is when I explore which subgroups have been most affected by these changes in the locations, I find that the incidence really falls on black men as a subgroup. So just to kind of put it in very simple and stark terms, black men growing up in Detroit, which was one of the most important Great Migration destination cities compared to black men growing up in Pittsburgh, which was more at the median in terms of being a destination - those growing up in Detroit are going to have lower household income as adults, even if they grew up in similarly resourced families with identical parent income as those growing up in Pittsburgh.

 

Jennifer [00:26:56] And you also looked at gender differences, right? So it wasn't just black men versus everyone else. You were looking at white men and black women. What did you find for those two groups?

 

Ellora [00:27:06] So I found that basically all of the incidence is falling on black men. And what do I mean by that? I mean, I see no effects on white men or women of having grown up in a Great Migration commuting zone. So that sort of the unit of analysis I'm looking at, which will be important when we talk about local public investments. For black women, interestingly, I see also no effect of having grown up in a Great Migration commuting zone on their adult household income. But actually, when I dig deeper, I see that this is really masking what looks like an income effect. And what I mean by that is I see that for black women growing up in Great Migration cities, they actually have higher, if anything, individual earnings than those growing up in non-destinations. So what that's consistent with is because the men that they typically form households with as adults have lower income. Black women are actually marrying less and working more in destination locations. And those two effects kind of cancel each other out. Now, that compensatory response by black women isn't enough to shield average black household income overall from these reductions. So actually, this reaction to the Great Migration - this change in the destination locations can explain over a quarter of the gap in upward mobility between black and white households in the region today.

 

Jennifer [00:28:43] You run a few robustness checks to make sure that your empirical strategy is measuring the effect of the Great Migration itself and not other possibly confounding factors. You've mentioned a couple considerations already. So you control for stuff like the decline in manufacturing and changes in European immigrant labor. You also consider the effects of white southern migration as a placebo test, which I really liked. So tell us about those tests and how they convince you that your empirical strategy is isolating the effect of the influx of new black residents.

 

Ellora [00:29:14] Yeah, so as you mentioned just now, one of the things that I control for is the manufacturing's share in the destination locations in the baseline period, so around 1940. And it turns out that that simple measure is highly predictive of the manufacturing share in 1950, in 1960, and even by 1970 the correlation is something like 0.7 or 0.8. But still we might worry - and this is really the most important alternative story here, which is just an unlucky choice of destination. Did black migrants move to places that looked good at the time, those places underwent economic decline, and now we're stuck with the kind of patterns that we see today. So what I also did is construct a Bartik instruments or the classic Bartik instrument for employment changes using variation in industrial composition across locations. So this is really very similar to the migration instrument that I'm using, but instead looking at how fluctuations nationally in employment in certain industries can predict declines in employment locally. But this really seems to have no impact on these contemporary upward mobility outcomes.

 

Ellora [00:30:36] The other key thing to point out is - you know, if we really thought that the Great Migration story here was instead picking up the effects of deindustrialization, I would really have expected that white men growing up in low income families would be affected by that. We know that the decline in manufacturing didn't just affect black people. White working class families were also affected. So that to me sort of suggested this has more to do with the change in the racial composition of these areas than changes in industrial structure.

 

Jennifer [00:31:17] In the paper, you highlight two possible reasons that upward mobility might fall on average in a place when a new group of people moves into that community. It could be, as you mentioned earlier, a simple compositional effect if the newcomers are different from the incumbent residents. So in this case, that would mean that the black southerners who moved in were worse off in various ways that might have limited their economic prospects regardless of their new communities characteristics. The other possible explanation for the decline in upward mobility that you're measuring is that incumbent residents responded to the influx of black residents in a way that actively reduced opportunity for people who lived there. So perhaps they reduced their spending on schools, for instance. So you do some work to try to tease these two explanations apart. Tell us how you convince yourself that the effects you're seeing are coming from a change in the community's characteristics rather than that simple compositional effect?

 

Ellora [00:32:08] Absolutely. So first, you know, just a kind of descriptive historical fact that was useful for me in distinguishing these two stories. If you take the story that really it's about the types of families - of black families in particular that were migrating out of the south, you can sort of look descriptively in the historical censuses at outcomes for black kids in the 1920s, 30s, and 1940 based on where their parents came from. And just one descriptive fact that I think ends up somewhere in the paper's appendix is that those children whose parents came from the south were more likely to stay in school longer than black children whose parents were already northern incumbents. So that's pretty interesting. And if you look at the characteristics of the migrants themselves, they tended to be actually a bit positively selected on the education dimension. So you can almost imagine these families that were leaving the south because they were at the ceiling in terms of providing opportunities for their children. In 1940, as a black family, you couldn't send your kids to public high school in the south. So the north was sort of your main option at that time.

 

Ellora [00:33:28] Now, the second - you know, and the most important thing I do to disentangle these two stories is to actually use a data set of upward mobility statistics that try to reflect the causal effect locations have on children's long run outcomes. So this is a data set once again that comes from the Opportunity Insights page that utilizes tax records and focuses on families that have moved across commuting zones in the US over the last, you know, roughly 30 years or so. And what the data set captures is - you can imagine four families all moving from one origin city, two of them move to Detroit and two of them move to Pittsburgh. Now, suppose that in each set of families, you have one family with kids that are eight years old and another with kids that are nine years old. So the family - and when you compare the two families that move from the origin location to Detroit. In one family, the kids are going to be exposed to Detroit for one year longer than the other, in particular the eight year olds, and the same is true for the families that move to Pittsburgh. So now the prediction here that I would make based on the findings so far is that that one additional year of childhood exposure to Detroit - remember, that's the major Great Migration destination - compared to one additional year of childhood exposure to Detroit - you know that exposure to Detroit is going to actually lower adult income more than that additional year of exposure to Pittsburgh, where Pittsburgh, again, was more at the median in terms of being a Great Migration destination. So I'm actually going to find exactly that. I'm going to be able to estimate the causal effect of the migration on adult income through just one year - one additional year of childhood exposure to a great migration destination.

 

Ellora [00:35:42] And when I scale that effect by how would that effect magnify after spending your entire childhood in a Great Migration destination? I find that that effect is the entire magnitude of the effect I told you about earlier. So you'll recall I found that a one standard deviation increase in black migration historically is associated with a 12% reduction in adult household income for individuals growing up in low income families there. All of that decline comes through the environment that you were exposed to as opposed to the kind of family that you grew up in. So that's the kind of key finding where I can really feel - I can argue that the changes in upward mobility stem from changes in the quality of the environment.

 

Jennifer [00:36:34] And then you use your original approach to dig in a little bit more to the quality of the environment and measure the effects of the Great Migration on various community characteristics that could be driving this change and upward mobility, so things like schooling and local government spending and crime rates and incarceration rates. So what do you find there?

 

Ellora [00:36:52] So first, you know, again, I mentioned that I collect these data going back roughly to 1920, because I want to understand, you know, what do these places look like in terms of government investments, schooling patterns, residential patterns prior to, during, and after the Great Migration. And so what I'm going to find importantly is that on most dimensions, destination locations and non-destination locations look really balanced, for example, on private school enrollment rates, on police investments, et cetera. One exception to that actually is murder rates were historically high in Great Migration destination locations. So to make sure that all of my findings are robust to controlling for historical urban murder rates - and that's going to be important later on. Then I observe basically the following things, residential segregation, which I should also mention, you know, from the time where, you know, black communities existed in the northern United States, they were segregated. So I want to also highlight that. But what I see is that these destination locations become more segregated over the 1940 to 1970 period, and they are more persistently, you know, segregated today after we've had a period of decline in segregation nationally.

 

Ellora [00:38:20] The second thing that I document is that local governments increase investment in one particular public service in response to black migrants moving in, and that is police. Now, one could, you know, hypothesize that that is just in direct response to higher urban murder rates that start, you know, occurring in the - in the late 60s and 70s and also persist in these locations. And that's also robust to controlling for historical murder rates. And it's really impossible for me to kind of disentangle with these data and with this approach, this kind of chicken and the egg story. I do notice that investments in policing seem to increase a little bit ahead of the kind of national crime wave that unfolds in the 1970s. But again, I can't quite disentangle these stories. But one thing I do see is that incarceration rates are higher for non-whites in Great Migration locations as early as 1960, and that this really persists through the 90s. So that's a very persistent effect.

 

Ellora [00:39:35] And there's a lot of literature that documents the kind of unequal incidence of our criminal justice policies across the population, as well as many negative spillovers in terms of racial inequality. So black men in particular are a group that are disproportionately affected by criminal justice policies. Now, when I think about the kids that I'm studying - and it's important to mention that they are kids, I'm thinking about characteristics of your childhood commuting zone that affect your life as an adult. That makes me think that it's probably not because little black boys are going around murdering people that the criminal justice system is explaining some of the reduction in their upward mobility. So I think that's an important thing to mention when we look at all of these findings and all of these changes that are occurring in the destination locations.

 

Jennifer [00:40:31] Yeah, and also, I mean, especially as we're in this moment where we're having a national conversation about whether our standard criminal justice interventions are, in fact, the best way to reduce crime. One could imagine a different scenario where in response to the same homicide rates, these cities chose a different path. Right. And invested in something other than police. Is that sort of the counterfactual you have in mind?

 

Ellora [00:40:56] Yeah. So, you know, I'm looking at commuting zones. And the reason I do that is because I want to capture the movement to the suburbs, you know, as part of the reaction to black migration into these locations. So at the commuting zone level, it's a little bit tricky to look at local government investments because local governments range in size from individual municipalities, school districts to the county level, et cetera. So the strategy that I use is to take a geographic area like a commuting zone and ask the question of all the local governments that are geographically located in the commuting zone, how is their money allocated? And that allows me to say, okay, at the commuting zone level, all together, local governments are investing in X and not Y. And so what I see is that pool together at the commuting zone level, the main investment that increases is police, whereas you might have imagined - in a situation where you have a large inflow of families, remember, at the ceiling in terms of the kind of education they provide for their kids in the south, migrating north, and finally being able to send their kids to public school, you could imagine that that would be a time to really invest in the education system. But that's not what I see.

 

Ellora [00:42:24] Looking at this from the commuting zone level means that I could be kind of averaging out a reallocation of education spending within commuting zones. And I think that's probably what's going on. For example, you could imagine that investments in education and school quality is kind of resorting out of urban schools and into suburban schools. And the pattern of white families sorting into private schools and black families being concentrated in public schools is very consistent with that. It's suggestive of a decline in the quality of the public school system that I may not be picking up with school spending alone. So that's a kind of caveat I want to put on that. But absolutely, if we're thinking about - you know, I always say that my paper is not a policy paper. I'm trying to really understand and document how Great Migration destinations changed in reaction to the migrants coming in. But, you know, if we - if you were to push me and say, well, what should we try first, I would absolutely say let's look at the criminal justice system. How can we try to find alternatives to community safety that might have, you know, not only positive effects on safety, but also not - eliminate these kind of other negative spillovers that have been documented time and time again?

 

Jennifer [00:43:51] Do your results imply that black residents in the north today are actually worse off than if their families had stayed in the south?

 

Ellora [00:43:57] So the key counterfactual that I was looking at in this study is if you grow up - you know, within the north, if you grow up in a place that was a major Great Migration destination city versus a place less affected by the migration, how do your adult outcomes change? So that's very - specifically the counterfactual I was interested in. And it's important for understanding what Great Migration locations are like for the grandchildren of the original migrants. But what that design does not address is, you know, that other question - a very important question which you just raised is essentially should the Great Migration have happened? But that is such an important question that I did take the time to try to think that through. And the short answer is yes, absolutely. I think it should have happened. And here's why. What the Great Migration did and others have documented this time and time again, is it vastly improved earnings for the migrants. As a black migrant moving north during the Great Migration, taking selection of migrants into account, you could double your earnings. What that does is move black grandparents from the vantage point of the generation I'm looking at - which is actually my generation - what that does is move black grandparents up in the national income distribution. And I hate to say it, and it's really unfortunate. One of the best things for your own kind of upward mobility or your family's upward mobility is to move your parents up the income distribution. So walking up that intergenerational mobility curve.

 

Ellora [00:45:39] Now, it's true that in the counterfactual where the Great Migration didn't happen, what I'm arguing is that black children in the north would get more out of every dollar of parent income than black children in the south. So imagine taking the intergenerational mobility curve and shifting it up. For black families, it would have been higher in the north than the south in the absence of the Great Migration. But today we're in a situation where those lines have converged and you get no more as a black child out of a dollar of parent income in the south versus the north. But in the world without the Great Migration, only 20% of black children would have enjoyed that higher line because 80% of the population would have still been in the south. So it's those two forces, the fact that more of the black population was in the north and allowed those grandparents to move up the income distribution, that cancels out this convergence of the two intergenerational mobility curves for black families, you know, in the north versus the south. And because of that canceling out, I would say yes, on net, the Great Migration did have a positive effect.

 

Ellora [00:46:54] And there are also effects that I haven't even taken into account here. For example, the emigration of black people out of the south put pressure on southern jurisdictions. They were basically hemorrhaging their main labor pool to finally start providing some of those public goods. And this is a phenomenon known as voting with your feet. And other scholars have kind of documented this effect. The second important piece that I've completely left out is that the Great Migration allowed black people to start voting in the north. So voting with your feet and actually voting at the ballot box for politicians who would support the Civil Rights Act. And where did the Civil Rights Act have its most important effects? In the South. So without the Great Migration, we may not have had a better south, and that other side of the convergence might not have happened. So those are all the reasons why I really think, yes, of course, the Great Migration was a huge milestone in black economic progress in the US overall.

 

Jennifer [00:47:57] So that is your paper. Is there other recent research that contributes to our understanding of how communities and neighborhoods affect economic mobility?

 

Ellora [00:48:05] Yes. There is - that - there's a lot of work out there. I might, you know, want to sort of spin that question a little bit. I think there's a lot of work that's kind of focused on what are the effects for families if we move them to higher opportunity neighborhoods, including some new work coming out of Raj Chetty's team and his collaborators on, you know, providing information to families about what are the high opportunity locations and, you know, giving them holistic support. And they're finding, you know, that actually helps people decide to move to high opportunity locations. And the pivot that I would suggest is, you know, we can always help a small fraction of families that way, you know, the recipients of HUD vouchers or housing lottery winners. But we're going to leave most people ultimately where they are or we're going to move so many people that we change locations. You know, that's kind of one of the main takeaways for my paper is that location effects are endogenous. And in response to large shocks, locations can change. So I would really encourage and I would love to see more research on specific, you know, local government policies and decisions that might change the quality of the locations - you know, basically place based policies that improve things where most poor people and low income people are. You know what can we experiment on from that perspective?

 

Ellora [00:49:43] So there's some really fascinating work on - coming to the other side, the education piece, which I don't focus a ton on in my paper because, you know, the criminal justice piece was so obviously important there. But there's some fantastic work looking at school integration, which was deemed a sort of policy failure because of the visceral reaction of a lot of white families and opposition to integration, but the scholarship is shown that school integration actually improved outcomes for black kids, not only their educational outcomes, but their long run outcomes in many other dimensions. So I'm thinking of Rucker Johnson's book, "Children of the Dream," and there's another recent paper by Cody Tuttle, who's just graduated from University of Maryland and looks at a school integration program in Kentucky. And he actually goes into restricted census data and finds that black children exposed to that program have better neighborhood outcomes later on in life. So policies like that that really address segregation, I think we should be thinking about that - or as I prefer to put it, policies that encourage integration. That's an area that I think people haven't really returned to in terms of policy. So I would like to kind of point that out as one direction.

 

Jennifer [00:51:09] Yeah. So you mentioned policy implications a little bit earlier. I'm going - I'm going to push you on it again. What would you say are the big policy implications of your own work and other work in this area? If policymakers came to you and said, what do I do with this? What are the main takeaways you'd want them to take with them?

 

Ellora [00:51:28] So, again, I would come back to this what I have called the sort of smoking gun in my analysis. What I'm finding is that black boys growing up in these former high opportunity cities, these cities that were known as Promised Land, they are disadvantaged by the time that they become adults and are in the labor market or not in the labor market, as the case may be. And that - I really want to drive home is through no fault of their own. You know, where people are born is one of the most consequential things in your life and you have no choice over this. And so given that black boys in particular are so affected by, you know, what appear to be the priorities and choices of policymakers locally, we really, really need to think about our criminal justice system in the US. And how much is it contributing to one of the most persistent forms of inequality in this country?

 

Ellora [00:52:37] So there are so many papers, and, you know, you are the expert on this, documenting the effects of various criminal justice policies on racial inequality. Let's take those seriously and start experimenting with policies that can reduce incarceration numbers and reduce the reach of criminal justice systems into children's lives, whether that's through their parents, through direct contact with the criminal justice system themselves, et cetera. So at the end of the day, I guess the best term is kind of let's figure out de-carceral policies. How do we undo the reach of the carceral state and people's lives?

 

Jennifer [00:53:26] Yeah, I am - often find myself telling grad students, you know, the question of like, does racial bias exist in the criminal justice system or do racial disparities exist as that has been answered? And now the question is, what do we do about it? Right. And how do we mitigate those effects or undo them? So that is a big research frontier. And you mentioned a couple other big research questions before, but are there any other big questions in this area that you will be thinking about or that you would encourage other PhD students perhaps to pick up and run with?

 

Ellora [00:54:00] Yes, absolutely. So one of the things that I'm working on now and thinking about a lot right now is, you know, one can say - looking at the history that black people in America have always acted very rationally. So in the early to mid-20th century, they moved en masse to opportunity. And I would still argue that that was the right decision. Starting in the 1970s, the direction of migration for black Americans reversed. And from 1970 to today, black Americans have actually been moving back to the south. The other thing they've been doing in dramatic numbers is moving out of cities and into suburbs.

 

Ellora [00:54:48] And if you just look at black versus white suburbanization rates in the US over time, you know, you can almost plot out the period of essential total exclusion from suburban housing markets through basically 1970. Black suburbanization rates are so low up until that point. Then - happens to line up very well with the Fair Housing Act. I think it's still an open question how much of an effect that had. But after 1970, black suburbanization rates start to increase dramatically and the increase, you know, it seems predominantly in the south. And so a huge open question that is, you know, difficult to take on data wise, but maybe I'm just drawn to those kinds of challenges, is what effect has that had? Have black families been able to achieve or finally arrive at some form of the American dream through this reverse migration and suburbanization? And we don't know. We do know that a quarter of a million black people have left the city of Chicago over the last 20 or 30 years. We do know that Atlanta is swiftly becoming a kind of black Mecca and one of the most important and largest destinations for black Americans. We don't know if that's worked. So I think that's really important to follow the lead of black Americans in their migration history in the United States and try to evaluate whether this most recent movement has been successful.

 

Jennifer [00:56:19] My guest today has Ellora Derenoncourt from Princeton University, soon to be UC Berkeley. Ellora, thanks so much for doing this.

 

Ellora [00:56:26] Thanks for having me again. I really enjoyed it.

 

Jennifer [00:56:34] You can find links to all the research we discussed today on our website, probablecausation.com. You can also subscribe to the show there or wherever you get your podcasts to make sure you don't miss a single episode. Big thanks to Emergent Ventures for supporting the show and thanks also to our Patreon subscribers. This show is listener supported. So if you enjoy the podcast, then please consider contributing via Patreon. You can find a link in our website. Our sound engineer is John Keur with production assistance from Elizabeth Pancotti. Our music is by Werner and our logo was designed by Carrie Throckmorton. Thanks for listening and I'll talk to you in two weeks.