Welcome! I'm a senior data scientist at Netflix. I like to build systems that improve decision-making. Tools I regularly use for this purpose include Bayesian statistics, causal inference, and computational methods in R and Python. Before coming to Netflix I was a research scientist at Facebook, and before that I got my PhD from Stanford while consulting for UNICEF. This page has a collection of resources primarily compiled during my PhD, but I sometimes update it with new papers and tutorials. Feel free to connect on LinkedIn.

Research

Global, Regional, and National Levels and Trends in Under-5 Mortality Between 1990 and 2015, with Scenario-based Projection to 2030 (with Danzhen You, Lucia Hug, Priscila Idele, Daniel Hogan, Patrick Gerland, Jin Rou New, and Leontine Alkema). The Lancet 2015.

Abstract. In 2000, world leaders agreed on the Millennium Development Goals (MDGs). MDG 4 called for a two-thirds reduction in the under-5 mortality rate between 1990 and 2015. We aimed to estimate levels and trends in under-5 mortality for 195 countries from 1990 to 2015 to assess MDG 4 achievement and then intended to project how various post-2015 targets and observed rates of change will affect the burden of under-5 deaths from 2016 to 2030.

Segregation, Ethnic Favoritism, and the Strategic Targeting of Local Public Goods (with Eric Kramon and Amanda Lea Robinson). Comparative Political Studies 2017.

Abstract. This article demonstrates that ethnic segregation is a key determinant of public goods provision. We argue that this results from politicians' strategic engagement in ethnic favoritism: only when ethnic groups are sufficiently segregated can elites efficiently target their coethnics with local public goods. We test this expectation with fine-grained data from Malawi on the spatial distribution of ethnic groups, geolocated distributive goods (public and private), and the ethnic identities of political elites. We find that members of parliament provide more local public goods to their constituencies when ethnic groups are geographically segregated, but that this increased investment is primarily targeted toward coethnics. Thus, while segregation promotes overall public goods provision, it also leads to greater favoritism in the distribution of these goods. Our logic and evidence provide an elite-driven explanation for the considerable variation in ethnic favoritism and the under-provision of public goods in ethnically diverse settings.

Do Elections Improve Constituency Responsiveness? Evidence from U.S. Cities (with Darin Christensen). Political Science Research and Methods 2018.

Abstract. Do elections motivate incumbent politicians to serve their voters? In this paper, we use millions of service requests placed by residents in US cities to measure constituency responsiveness. We then test whether an unusual policy change in New York City, which enabled city councilors to run for three rather than two terms in office, improved constituency responsiveness in previously term-limited councilors’ districts. Using difference-in-differences, we find robust evidence for this. Taking advantage of differential timing of local election races in New York City and San Francisco, we also find late-term improvements to responsiveness in districts represented by reelection-seeking incumbents. Elections improve municipal services, but also create cycles in constituency responsiveness. These findings have implications for theories of representative democracy.

R Tutorials

Data Visualization

NYC Responsiveness

Since 2004 over 15 million service requests have been filed by residents in NYC. The government responds quicker in some neighborhoods than in others...

Ecological Footprints

On average, humanity's demand on biocapacity exceeds the world's natural capacity by 50%. Put differently, 1.5 planet Earths would be required...

Child Mortality & Wealth

While child mortality in general is lower in high-income countries, many low-income countries did a remarkable job of reducing it between 1990 and 2015...

Mortality Map

Despite significant progress in reducing child mortality over the last 25 years, 43 out of every 1000 children died before their fifth birthday in 2015....