Risk compensation after COVID-19 vaccination: Evidence from vaccine rollout by exact birth date in South Korea.

We utilize the phased rollout of COVID-19 vaccines by exact birth date in South Korea as a natural experiment for testing risk compensation. People may resume face-to-face social activities following vaccination because they perceive lower risk of infection. Applying a regression discontinuity design based on birth date cutoffs for vaccine eligibility, we find no evidence of risk-compensating behaviors, as measured by large, high-frequency data from credit card and airline companies as well as survey data. We find some evidence of self-selection into vaccine take-up based on perception toward vaccine effectiveness and side effects, but the treatment effects do not differ between compliers and never-takers.

Selection and behavioral responses of health insurance subsidies in the long run: Evidence from a field experiment in Ghana.

We study the effects of a health insurance subsidy in Ghana, where mandates are not enforceable. We randomly provide different levels of subsidy (1/3, 2/3, and full) and evaluate the impact at 7 months and 3 years after the intervention. We find that a one-time subsidy increased insurance enrollment for all groups in both the short and long runs, but health care utilization in the long run increased only for the partial subsidy group. We find supportive evidence that ex-post behavioral responses rather than ex-ante selective enrollment explain the long-run health care utilization results.

The Roles of Nutrition Education and Food Vouchers in Improving Child Nutrition: Evidence from a Field Experiment in Ethiopia.

Mothers' lack of knowledge about child nutrition and limited resources lead to poor diets among children in developing countries, increasing their risk of chronic undernutrition. We implemented a cluster randomized control trial that randomly provides four-month-long Behavior Change Communication (BCC) and food vouchers in Ethiopia. We find improvements in child-feeding practices and a reduction in chronic child undernutrition only when BCC and vouchers are provided together. BCC or voucher alone had limited impacts. Our results highlight the importance of adding an effective educational component to existing transfer programs.

Knowing is not half the battle: Impacts of information from the National Health Screening Program in Korea.

Health screening provides information on disease risk and diagnosis, but whether this promotes health is unclear. We estimate the impacts of information provided by Korea's National Health Screening Program by applying a regression discontinuity design around different biomarker thresholds of diabetes, obesity, and hyperlipidemia risk using administrative data that includes medical claims, biomarkers, and behavioral surveys over four years after screening. Generally, we find limited responses to disease risk information alone. However, we find evidence for weight loss around the high risk threshold for diabetes, where information is combined with active prompting for a secondary examination for diagnosis and treatment.

The role of education interventions in improving economic rationality.

Schooling rewards people with labor market returns and nonpecuniary benefits in other realms of life. However, there is no experimental evidence showing that education interventions improve individual economic rationality. We examine this hypothesis by studying a randomized 1-year financial support program for education in Malawi that reduced absence and dropout rates and increased scores on a qualification exam of female secondary school students. We measure economic rationality 4 years after the intervention by using lab-in-the-field experiments to create scores of consistency with utility maximization that are derived from revealed preference theory. We find that students assigned to the intervention had higher scores of rationality. The results remain robust after controlling for changes in cognitive and noncognitive skills. Our results suggest that education enhances the quality of economic decision-making.

When public health intervention is not successful: Cost sharing, crowd-out, and selection in Korea's National Cancer Screening Program.

This study investigates the impact of and behavioral responses to cost sharing in Korea's National Cancer Screening Program, which provides free stomach and breast cancer screenings to those with an income below a certain cutoff. Free cancer screening substantially increases the screening take up rate, yielding more cancer detections. However, the increase in cancer detection is quickly crowded out by cancer detection through other channels such as diagnostic testing and private cancer screening. Further, compliers are much less likely to have cancer than never takers. Crowd-out and selection help explain why the program has been unable to reduce cancer mortality.

Promotion and Persistence of HIV Testing and HIV/AIDS Knowledge: Evidence From a Randomized Controlled Trial in Ethiopia.

We use data from a randomized controlled trial in Ethiopia and examine the causal effects of HIV/AIDS education, home-based voluntary HIV counseling and testing (VCT), and conditional cash transfers (CCT) for facility-based VCT on HIV/AIDS knowledge and demand for HIV testing. HIV/AIDS education significantly increases HIV/AIDS knowledge but has a limited effect on testing take-up. However, when HIV/AIDS education is combined with either home-based VCT or CCT for facility-based VCT, take-up increases substantially by about 63 and 57 percentage points, respectively. We also demonstrate evidence of persistence in test-taking behavior, where past HIV testing does not dampen demand for testing. Lastly, we find suggestive evidence that home-based VCT could be more effective at detecting HIV-positive cases relative to CCT for facility-based VCT. Our findings highlight the importance of geographic accessibility in the testing decision and persistence in demand for HIV testing. Copyright © 2016 John Wiley & Sons, Ltd.