Automated census record linking: a machine learning approach

Thanks to the availability of new historical census sources and advances in record linking technology, economic historians are becoming big data genealogists. Linking individuals over time and between databases has opened up new avenues for research into intergenerational mobility, assimilation, discrimination, and the returns to education. To take advantage of these new research opportunities, scholars need to be able to accurately and efficiently match historical records and produce an unbiased dataset of links for downstream analysis. I detail a standard and transparent census matching technique for constructing linked samples that can be replicated across a variety of cases. The procedure applies insights from machine learning classification and text comparison to the well known problem of record linkage, but with a focus on the sorts of costs and benefits of working with historical data. I begin by extracting a subset of possible matches for each record, and then use training data to tune a matching algorithm that attempts to minimize both false positives and false negatives, taking into account the inherent noise in historical records. To make the procedure precise, I trace its application to an example from my own work, linking children from the 1915 Iowa State Census to their adult-selves in the 1940 Federal Census. In addition, I provide guidance on a number of practical questions, including how large the training data needs to be relative to the sample.This research has been supported by the NSF-IGERT Multidisciplinary Program in Inequality & Social Policy at Harvard University (Grant No. 0333403)

Capital Destruction and Economic Growth: The Effects of Sherman’s March, 1850-1920

Working paper.Using General William Sherman’s 1864--65 military march through Georgia, South Carolina, and North Carolina during the American Civil War, this paper studies the effect of capital destruction on short- and long-run local economic activity, and the role of financial markets in the recovery process. We match an 1865 US War Department map of Sherman’s march to county-level demographic, agricultural, and manufacturing data from the 1850–1920 US Censuses. We show that the capital destruction induced by the March led to a large contraction in agricultural investment, farming asset prices, and manufacturing activity. Elements of the decline in agriculture persisted through 1920. Using information on local banks and access to credit, we argue that the underdevelopment of financial markets played a role in weakening the recovery

How legislators respond to localized economic shocks: evidence from Chinese import competition

We explore the effects of localized economic shocks from trade on roll-call behavior and electoral outcomes in the US House, 1990–2010. We demonstrate that economic shocks from Chinese import competition—first studied by Autor, Dorn, and Hanson—cause legislators to vote in a more protectionist direction on trade bills but cause no change in their voting on all other bills. At the same time, these shocks have no effect on the reelection rates of incumbents, the probability an incumbent faces a primary challenge, or the partisan control of the district. Though changes in economic conditions are likely to cause electoral turnover in many cases, incumbents exposed to negative economic shocks from trade appear able to fend off these effects in equilibrium by taking strategic positions on foreign-trade bills. In line with this view, we find that the effect on roll-call voting is strongest in districts where incumbents are most threatened electorally. Taken together, these results paint a picture of responsive incumbents who tailor their roll-call positions on trade bills to the economic conditions in their districts

Multiple measures of historical intergenerational mobility: Iowa 1915 to 1940

This paper was previously circulated under the title “A New Old Measure of Intergenerational Mobility: Iowa 1915 to 1940”.Was intergenerational economic mobility high in the early twentieth century in the United States? Comparisons of mobility across time are complicated by the constraints of the data available. I match fathers from the Iowa State Census of 1915 to their sons in the 1940 Federal Census, the first state and federal censuses with data on income and years of education. With this linked sample, I can estimate intergenerational mobility between 1915 and 1940 based on earnings, education, occupation, and names. Across all these measures, I document broad consensus that rates of persistence were low in Iowa in the early twentieth century. Within my sample, rural sons from Iowa had more intergenerational mobility than their urban peers and the grandchildren of the foreign-born were more mobile than the grandchildren of the native-born

The majority-party disadvantage: revising theories of legislative organization

Dominant theories of legislative organization in the U.S. rest on the notion that the majority party arranges legislative matters to enhance its electoral fortunes. Yet, we find little evidence for a short-term electoral advantage for the majority party in U.S. state legislatures. Furthermore, there appears to be a pronounced downstream majority-party disadvantage. To establish these findings, we propose a technique for aggregating the results of close elections to obtain as-if random variation in majority-party status. We argue that the results from this approach are consistent with a phenomenon of inter-temporal balancing, which we link to other forms of partisan balancing in U.S. elections. The article thus necessitates revisions to our theories of legislative organization, offers new arguments for balancing theories, and lays out an empirical technique for studying the effects of majority-party status in legislative contexts

Intergenerational mobility during the Great Depression

Unpublished working paper.Do severe economic downturns increase intergenerational economic mobility by breaking links between generations, or do they instead reduce mobility by limiting opportunity for the young? To answer this question, I estimate rates of intergenerational mobility during the Great Depression for individuals in American cities that experienced downturns of varying severity. I create two new historical samples, digitizing and transcribing archival data on individual earnings and linking fathers to sons before and after the Depression. To build these longitudinal samples, I develop a new machine learning approach to census matching, which enables me to link individuals accurately and efficiently between censuses in the absence of unique identification numbers. I find that the Great Depression lowered intergenerational mobility for sons growing up in cities hit by large downturns. These results are not driven by place-specific mobility differences: for the generation before the Depression, mobility between 1900 and 1920 is unrelated to future downturn intensity. Differential directed migration is a key mechanism to explain my results. Although sons fled distressed cities at similar rates, the sons of richer fathers migrated to locations that had suffered less severe Depression effects. The differences in rates of intergenerational mobility for sons in the most and least Depression-affected cities are comparable to the differences between the United States and Sweden today

The Vicious Cycle: Fundraising and Perceived Viability in U.S. Presidential Primaries

Scholars of presidential primaries have long posited a dynamic positive feedback loop between fundraising and electoral success. Yet existing work on both directions of this feedback remains inconclusive and is often explicitly cross-sectional, ignoring the dynamic aspect of the hypothesis. Pairing high-frequency FEC data on contributions and expenditures with Iowa Electronic Markets data on perceived probability of victory, we examine the bidirectional feedback between contributions and viability. We find robust, significant positive feedback in both directions. This might suggest multiple equilibria: a candidate initially anointed as the front-runner able to sustain such status solely by the fundraising advantage conferred despite possessing no advantage in quality. However, simulations suggest the feedback loop cannot, by itself, sustain advantage. Given the observed durability of front-runners, it would thus seem there is either some other feedback at work and/or the process by which the initial front-runner is identified is informative of candidate quality

Regional and racial inequality in infectious disease mortality in U.S. cities, 1900-1948

In the first half of the twentieth century, the rate of death from infectious disease in the United States fell precipitously. Although this decline is well-known and well-documented, there is surprisingly little evidence about whether it took place uniformly across the regions of the U.S. We use data on infectious disease deaths from all reporting U.S. cities to describe regional patterns in the decline of urban infectious mortality from 1900 to 1948. We report three main results: First, urban infectious mortality was higher in the South in every year from 1900 to 1948. Second, infectious mortality declined later in southern cities than in cities in the other regions. Third, comparatively high infectious mortality in southern cities was driven primarily by extremely high infectious mortality among African Americans. From 1906 to 1920, African Americans in cities experienced a rate of death from infectious disease greater than what urban whites experienced during the 1918 flu pandemic.First author draf

Born-Regulated Gravity in Four Dimensions

Previous work involving Born-regulated gravity theories in two dimensions is extended to four dimensions. The action we consider has two dimensionful parameters. Black hole solutions are studied for typical values of these parameters. For masses above a critical value determined in terms of these parameters, the event horizon persists. For masses below this critical value, the event horizon disappears, leaving a ``bare mass'', though of course no singularity.Comment: LaTeX, 15 pages, 2 figure

When coercive economies fail: the political economy of the US South after the boll weevil

How do coercive societies respond to negative economic shocks? We explore this question in the early 20th-Century United States South. Since before the nation's founding, cotton cultivation formed the politics and institutions in the South, including the development of slavery, the lack of democratic institutions, and intergroup relations between whites and blacks. We leverage the natural experiment generated by the boll weevil infestation from 1892-1922, which disrupted cotton production in the region. Panel difference-in-differences results provide evidence that Southern society became less violent and repressive in response to this shock with fewer lynchings and less Confederate monument construction. Cross-sectional results leveraging spatial variation in the infestation and historical cotton specialization show that affected counties had less KKK activity, higher non-white voter registration, and were less likely to experience contentious politics in the form of protests during the 1960s. To assess mechanisms, we show that the reductions in coercion were responses to African American out-migration. Even in a context of antidemocratic institutions, ordinary people can retain political power through the ability to "vote with their feet."First author draf