Knowledge that Transforms

This paper presents the first systematic investigation of the effect of epidemic shocks on civil violence. The identification exploits exogenous within cell × year variation in conditions that are suitable for malaria transmission using a panel database with month-by-month variation at a resolution of 1∘×1∘ latitude/longitude for Africa. Suitable conditions increase civil violence in areas with populations susceptible to epidemic outbreaks. The effect is immediate, related to the acute phase of the epidemic and largest during short harvesting seasons of subsistence crops. Genetic immunities and antimalaria policies attenuate the effect. The results deliver new insights for prevention and attenuation policies and for potential consequences of climate change.

I study the effects of prison quality on recidivism using individual-level data from Colombia. To estimate causal effects, I leverage the quasi-random assignment of inmates to newer, less crowded, and higher service prisons. For inmates assigned to newer facilities, I find that the probability of returning to prison within one year is 36% lower. Criminal capital, access to rehabilitation programs, and negative prison experiences, which could trigger changes in intrinsic preferences over illegal occupations, seem to be important mechanisms. The program led to substantial welfare gains, even when assuming a low social cost per crime.

We develop a Bayesian latent factor model of the joint long-run evolution of GDP per capita for 113 countries over the 118 years from 1900 to 2017. We find considerable heterogeneity in rates of convergence, including rates for some countries that are so slow that they might not converge (or diverge) in century-long samples, and a sparse correlation pattern (“convergence clubs”) between countries. The joint Bayesian structure allows us to compute a joint predictive distribution for the output paths of these countries over the next 100 years. This predictive distribution can be used for simulations requiring projections into the deep future, such as estimating the costs of climate change. The model's pooling of information across countries results in tighter prediction intervals than are achieved using univariate information sets. Still, even using more than a century of data on many countries, the 100-year growth paths exhibit very wide uncertainty.

Local pollution exposures have a disproportionate impact on minority households, but the root causes remain unclear. This study conducts a correspondence experiment on a major online housing platform to test whether housing discrimination constrains minority access to housing options in markets with significant sources of airborne chemical toxics. We find that renters with African American or Hispanic/Latinx names are 41% less likely than renters with white names to receive responses for properties in low-exposure locations. We find no evidence of discriminatory constraints in high-exposure locations, indicating that discrimination increases relative access to housing choices at elevated exposure risk.

I study how supplier contracting frictions shape the patterns of intermediate input use and quantify the impact of these distortions on aggregate productivity. Using the frequency of litigation between US firms as a novel measure to capture the need for formal enforcement, I find a robust relationship between countries' input-output structure and their quality of legal institutions. In countries with high enforcement costs, firms have lower expenditure shares on intermediate inputs in sector pairs where US firms litigate frequently for breach of contract. A quantitative model shows that improvement of contract enforcement institutions would lead to sizable welfare gains.

As in other OECD countries, women in New Zealand earn substantially less than men with similar observable characteristics. In this paper, we use fifteen years of linked employer-employee data to examine different explanations for this gender wage gap. We find an overall gender wage gap between 20% and 28%, of which gender differences in sorting across occupations explain 9%, across industries 16% to 19%, and across firms 5% to 9%, respectively. The remaining within-firm gender wage gap is still between 13% and 17%. Around 5 percentage points of this are explained by women being less willing to bargain or less successful at bargaining to capture firm-specific rents. Gender differences in productivity also explain at most 4.5 percentage points of this remaining gap. These results suggest that taste discrimination is also important for explaining why women are paid less than their relative contribution to firm output. Across-industry and over-time variation in the gender wage-productivity gap further support this conclusion.

We study the investment of organized crime in the legal economy. By using the shock induced on the Italian credit market by the 2007 subprime mortgage crisis, we document how provinces with a high organized crime presence have been affected less by the crisis in terms of the establishment of new enterprises than provinces with a lower criminal infiltration. We provide evidence that the lower impact of the crisis is consistent with the presence of investments by organized crime in the legal economy. We corroborate this interpretation by comparing our results with the characterization made by the judicial authority of such investments.

We develop a medium-size semistructural time series model of inflation dynamics that is consistent with the view, often expressed by central banks, that three components are important: a trend anchored by long-run expectations, a Phillips curve, and temporary fluctuations in energy prices. We find that a stable long-term inflation trend and a well-identified steep Phillips curve are consistent with the data, but they imply potential output declining since the new millennium and energy prices affecting headline inflation not only via the Phillips curve but also via an independent expectational channel.

We study the effects of prenatal exposure to violent crime on infant health, using New York City crime records linked to mothers' addresses in birth records data. We address endogeneity of assault exposure with three strategies and find that in utero assault exposure significantly increases the incidence of adverse birth outcomes. We calculate that the annual social cost of assault during pregnancy in the United States is more than $3.8 billion. Since infant health predicts long-term wellbeing and disadvantaged women are disproportionately likely to be domestic abuse victims, violence in utero may be an important channel for intergenerational transmission of inequality.

Applied work often studies the effect of a binary variable (“treatment”) using linear models with additive effects. I study the interpretation of the OLS estimands in such models when treatment effects are heterogeneous. I show that the treatment coefficient is a convex combination of two parameters, which under certain conditions can be interpreted as the average treatment effects on the treated and untreated. The weights on these parameters are inversely related to the proportion of observations in each group. Reliance on these implicit weights can have serious consequences for applied work, as I illustrate with two well-known applications. I develop simple diagnostic tools that empirical researchers can use to avoid potential biases. Software for implementing these methods is available in R and Stata. In an important special case, my diagnostics require only the knowledge of the proportion of treated units.