Count data regressions are an important tool for empirical analyses ranging from analyses of patent counts to measures of health and unemployment. Along with negative binomial, Poisson panel regressions are a preferred method of analysis because the Poisson conditional fixed effects maximum...

Empirical researchers often have to map data provided for a "reporting" spatial unit, say counties in 1900, to a "reference" one, say, counties in 2010. We discuss a general method to create such crosswalks: computing the share of the area of each reporting unit nested in a given reference unit....

We develop a framework to estimate the economic value of a recent zoning reform in the city of Sao Paulo, which altered maximum permitted construction at the city-block level. Using a spatial regression discontinuity design, we find that developers file for more multi-family construction permits...

We introduce a new methodology to detect and measure economic activity using geospatial data and apply it to steel production, a major industrial pollution source worldwide. Combining plant output data with geospatial data, such as ambient air pollutants, nighttime lights, and temperature, we...

In applied historical research, geographic units often differ in level of aggregation across datasets. One solution is to use crosswalks that associate factors located within one geographic unit to another, based on their relative areas. We develop an alternative approach based on relative...

This paper develops linear estimators for structural and causal parameters in nonparametric,nonseparable models using panel data. These models incorporate unobserved, time-varying, individual heterogeneity, which may be correlated with the regressors. Estimation is based on an approximation of...

In this paper, we provide a suite of tools for empirical market design, including optimal nonlinear pricing in intensive-margin consumer demand, as well as a broad class of related adverse-selection models. Despite significant data limitations, we are able to derive informative bounds on demand...

This paper analyzes and estimates the impact of quantity discounts for basic staples in rural Mexico. We propose a model of price discrimination that nests those of Maskin and Riley (1984) and Jullien (2000), in which consumers differ in their tastes and, due to subsistence constraints, in their...

Empirical models of demand for-and, often, supply of-differentiated products are widely used in practice, typically employing parametric functional forms and distributions of consumer heterogeneity. We review some recent work studying identification in a broad class of such models. This work...