Abstract: We study the behavior of cluster-robust test statistics in models with instrumental variables when cluster heterogeneity is present. Inference in a large number of papers using two-stage least squares regressions published in American Economics Association journals are driven by the presence of one or two influential clusters. We link a measure of cluster heterogeneity, the feasible effective number of clusters, to measures of influence. Using simulations, we demonstrate that high levels of cluster heterogeneity lead to coverage of less than 95% for 95% confidence intervals when using instrumental variables with panel data or with data that can be grouped into clusters. Using data from papers with two-stage least squares regressions published in American Economic Association journals, we show that the feasible effective number of clusters can be used as a pre-test to the sensitivity of two-stage least squares inference to influential clusters.
Weather and Malaria Incidence in Sub-Saharan Africa
Abstract: I study the impact of changing weather patterns on the incidence of malaria and the effectiveness of malaria initiatives in Sub-Saharan Africa between the years 2000 and 2015. Combining malaria incidence with climate reanalysis I estimate the impact of malarious weather on malaria prevalence and analyze the changing efficacy of malaria prevention and treatment.
Works in Progress
Abstract: How does the sharing economy affect home rental markets? The advent of platforms such as Airbnb in 2008 has introduced a new channel of market interaction between those with space and those who seek it. This allows for transactions of lodging services that might otherwise be underutilized. This paper develops a framework to help think about how peer-to-peer transactions interact with traditional rental markets, and what this means for landlords and tenants. Specifically, we examine how the introduction of sharing platforms (e.g. Airbnb) affect the listing decisions of vacant property owners and the lodging choices of dwelling seekers. The model features landlords who choose where to list vacant properties and renters who search for lodging. Renters can be either short-term or long-term, referencing how long they wish to occupy the property. Sharing platforms give landlords the option of accessing these short-term renters who would otherwise occupy hotels, affecting traditional, long-term renters.