With Gary Burtless
Soc. Sec. Bull. 73 (2013): 83.

The increasing cost of employer contributions for employee health insurance reduces the share of compensation subject to the Social Security payroll tax. Rising insurance contributions can also have a more subtle effect on the Social Security tax base because they influence the distribution of money wages above and below the taxable maximum amount. This article uses the Medical Expenditure Panel Survey to analyze trends in employer health insurance contributions and the distribution of those costs up and down the wage distribution. Our analysis shows that employer health insurance contributions increased faster than overall compensation during 1996-2008, but such contributions grew only slightly faster among workers earning less than the taxable maximum than they did among those earning more. Because employer health insurance contributions represent a much higher percentage of compensation below the taxable maximum, health insurance cost trends exerted a disproportionate downward pressure on money wages below the taxable maximum.

With Barry Bosworth
Washington, Brookings (2011)

Working Papers

Less Bite for your Buck: Using Cell Phone Data to Target Disease Prevention (Job Market Paper)

Infectious diseases have a large economic and social burden that is magnified by infected travelers who spread diseases to the locations they visit. In this paper, I study malaria transmission in Senegal by quantifying the relationship between travel and spread of the disease and showing its implications for targeting policies. Using individual mobile phone records for 9 million users in 2013, I estimate daily interregional movement and demonstrate substantial intertemporal and geographic variation in movement. I link this variation to clinic data on the incidence of malaria in order to calculate the probability a traveler is infected and to determine the impact in the area a traveler enters. Estimates indicate that an infected traveler entering a health facility's catchment area causes reporting of 1.6 additional cases. I apply the results to evaluate the potential for policies targeting travelers. At the same cost, strategic targeting of travelers from high-incidence locations would result in up to five times as many cases being averted as compared to current policies of randomly targeting travelers during the malaria season. These findings indicate how novel applications of big data, combined with traditional health measures, can enable improvements in policy to address negative spillovers from travel and lower the burden from communicable disease.

Household recombination, retrospective evaluation, and educational mobility over 40 years

With Andrew Foster

Despite longstanding belief in certain circles that investment in primary health care and education can help to encourage reductions in inequality and increases in intergenerational economic mobility, evidence is scarce due to the lack of systematically collected data from developing countries that links households over multiple decades. Bangladesh would seem an especially fruitful avenue for looking at these issues given international recognition of its success in improving basic health care and expanding primary education. In this paper we use newly collected survey data connected to the Matlab Demographic Surveillance System (DSS) maintained by the International Center for Diarrheal Disease Research in Bangladesh (ICDDRB) to take a first look at this issue. A novel insight from this paper is that standard methods for correcting sampling weights in panel data do not adequately account for the process of household formation and dissolution. We develop a new approach to weighting that requires the kind of information available in the context of a DSS, and use these weights to look at long term changes in educational investment of households in the Matlab area. We show that a substantial rise in average educational investment among children 6-16 has been accompanied by high levels of economic mobility but little reduction in economic inequality.

Long-Term Effects of the Matlab Maternal and Child Health and Family Planning Program on Cohort Survival and Health

With Jane Menken, Randall Kuhn, Patrick S. Turner, Tania Barham, Abdur Razzaque, Elisabeth Dowling Root, Andrew Foster, Warren Jochem, Gisella Kagy, Nobuko Mizoguchi

Late in the 1970s, icddr,b introduced its well-known maternal and child health and family planning program incrementally in approximately half the area in which their Matlab Health and Demographic Surveillance System collected data from all households at least quadrennially. Similar services were unavailable in the Comparison area for approximately a dozen years. Effects on period fertility and infant/child mortality were immediate. But did advantage last over the lifecourse? This is the first paper examining long-term effects (to 2014) on birth cohort survival and health. Treatment area survival increased almost immediately, with differences most pronounced in cohorts born 1978-87. Area differences narrowed thereafter. Cohort fertility results reveal sizeable bias when migrants are excluded from analysis. Further analysis will utilize extensive recently collected migrant follow-up data to continue this unprecedented opportunity for long-term evaluation. Preliminarily, when migrants are included, some cohorts show treatment area advantage in survival at older ages.

Predicting Dynamic Patterns of Short Term Movement

Short term human mobility has important health consequences, yet measuring short term movement, especially in low income countries, using survey data has been difficult, and recent use of mobile phone data to study short term movement for a whole country is only possible in locations that can access the data. Putting together data that is much more easily available for the majority of low income countries, I use Senegal as a case study to predict short term movement within the country. To study short term movement, I focus on two main drivers: economic and social. I find that some of the most important predicting factors of short term movement are related to distance between regions and the economic activity of regions as measured using lights data. I am able to explain almost 70% of the variation in short term movement using a number of measures of economic and social drivers. In addition, the predictions generated by my model can provide good estimates for the effect of short term movement on malaria, demonstrating how predictions of short term movement can be used in contexts where data on this movement are not available, in order to understand its consequences.

Work in Progress

Understanding the Relationship Between Short Term Mobility and Long Term Migration Patterns

With Elisabeth zu Erbach-Schoenberg, Linus Bengtsson Erik Wetter, Andy Tatem

Bias in Measuring Population Movement Using Mobile Phone Data: Utilization of Randomly Generated "Robo-calls"

Effects of oil price shocks on overseas guest worker migration: Evidence from Bangladesh

With Randall Kuhn