In the mid-19th century, the urban milk supply in the United States was regularly skimmed or diluted with water, reducing its nutritional value. At the urging of public health experts, cities across the country hired milk inspectors, who were tasked with collecting and analyzing milk samples...

This paper reports estimates of consumers' preferences for plans to improve food safety. The plans are distinguished based on whether they address the ex ante risk of food borne illness or the ex post effects of the illness. They are also distinguished based on whether they focus on a public...

We report a large-scale randomized controlled trial designed to assess whether the partisan cue of a provaccine message from Donald Trump would induce Americans to get COVID-19 vaccines. Our study involved presenting a 27-second advertisement to millions of U.S. YouTube users in October 2021....

Measuring the returns of advertising opportunities continues to be a challenge for many businesses. We design and run a field experiment in collaboration with Yelp across 18,294 firms in the restaurant industry to understand which types of businesses gain more from digital advertising. We...

COVID-19 vaccines are widely available in wealthy countries, yet many people remain unvaccinated. Understanding the effectiveness -- or lack thereof -- of popular vaccination campaign strategies is therefore critical. In this paper, we report results from two studies that tested strategies...

Third-party cookies and related 'offsite' tracking technologies are frequently used to share user data across applications in support of ad delivery. These data are viewed as highly valuable for online advertisers, but their usage faces increasing headwinds. In this paper, we quantify the...

We exploit variation in the composition of local fish catches around the time of birth using administrative and census data on adult cognitive test scores, schooling attainment, and occupation among coastal populations in Colombia to estimate the causal effects of early-life consumption of...

Using proprietary data from Alibaba, we examine how the 2015 Food Safety Law (FSL) affects e-commerce in China. The FSL requires most food sellers on e-commerce platforms to obtain a valid, online license for retail food handling. Because the FSL was rolled out progressively, we have a rare...

In the United States, drug safety and efficacy are primarily regulated by the Food and Drug Administration (FDA) and the legal system, which gives manufacturers large incentives to produce safe drugs and provide proper warnings for side effects, since patients can sue manufacturers that provide...

Comparing the safety of prescription drugs over time is difficult due to the paucity of reliable quantitative measures of drug safety. Both the academic literature and popular press have focused on drug withdrawals as a proxy for breakdowns in the drug safety system. This metric, however, is...