Research

Working Papers

"Social Stigma as a Barrier to HIV Testing: Evidence from a Randomized Experiment in Mozambique." [PDF] [AEA Registry]


  • Abstract: Public health experts have seen the stigma as a leading barrier affecting the delivery of HIV-related health care. By using a field experiment in Mozambique, this study identifies the role of stigma concerns in hindering HIV testing and quantifies the stigma barrier. To obtain local measures of the HIV stigma environment in the study sites, we conducted a baseline survey one year before the experiment. Experiment participants with excessive concerns, defined as overestimating the stigma in their communities, were randomly assigned an intervention to relieve stigma concerns. The intervention, which drew upon findings from the baseline survey, was designed to reveal the correct degree of stigma that a participant had overestimated. Analyses show that this intervention raised the HIV test uptake rate by 7.7 percentage points (or by 37 percent) from 20.7 percent under the control condition. To quantify the intervention effect, I introduced testing coupons of different values to estimate the demand curve for an HIV test. The concern-relieving intervention raised an individual’s willingness-to-pay for an HIV test by $1.30, or more than half of the daily cost-of-living in the study population.

“Knowledge, Stigma, and HIV Testing: An Analysis of a Widespread HIV/AIDS Program,” with Dean Yang, Arlete Mahumane, James Riddell, and James Allen. NBER Working Paper. [PDF]

A previous version under the title “Direct and Spillover Impacts of a Community-Level HIV/AIDS Program: Evidence from a Randomized Controlled Trial in Mozambique” is accepted based on pre-results review at the Journal of Development Economics, July 2019.[PDF] [ClinicalTrials.gov Registry] [AEA Registry]

  • Abstract: Using randomized methodologies, we study a common community HIV/AIDS program that seeks to promote HIV testing by improving knowledge and reducing stigmatizing attitudes. Contrary to expectations, the program has a substantial negative effect on HIV testing rates. We provide evidence of likely mechanisms behind the program’s negative effect: it inadvertently increased misinformation about HIV, and worsened HIV-related stigmatizing attitudes. Subsequent household-level randomized treatments providing correct information and addressing stigma concerns counteract the program’s negative effect on HIV testing. These findings highlight the importance of improving knowledge and alleviating stigma concerns when promoting HIV testing.

"Correcting Perceived Social Distancing Norms to Combat COVID-19." with James Allen, Arlete Mahumane, James Riddell, Tanya Rosenblat, and Dean Yang. NBER Working Paper. [PDF] [AEA Registry]

  • Abstract: Can informing people of high rates of community support for social distancing encourage them to do more of it? Our Mozambican study population underestimated the rate of community support for social distancing, believing support to be only 69%, while the true share was 98%. In theory, informing people of high rates of community support has ambiguous effects on social distancing, depending on whether a perceived-infectiousness effect dominates a free-riding effect. We randomly assigned a "social norm correction'' treatment, informing people of true high rates of community support for social distancing. We examine an improved measure of social distancing combining detailed self-reports with reports on the respondent by others in the community. The treatment increases social distancing where COVID-19 caseloads are high (where the perceived-infectiousness effect dominates), but decreases it where caseloads are low (where free-riding dominates). Separately, randomized local-leader endorsements of social distancing are ineffective. As COVID-19 caseloads continue to rise, interventions such as the "social norm correction'' treatment should show increased effectiveness at promoting social distancing.

Teaching and Incentives: Substitutes or Complements?”, with Dean Yang, James Allen, Arlete Mahumane, James Riddell, and Tanya Rosenblat. NBER Working Paper. [PDF] [AEA Registry]

  • Abstract: Interventions to promote learning are often categorized into supply- and demand-side approaches. In a randomized experiment to promote learning about COVID-19 among Mozambican adults, we study the interaction between a supply and a demand intervention, respectively: 1) teaching, and 2) providing financial incentive to learners. In theory, teaching and learner-incentives may be substitutes (crowding out one another) or complements (enhancing one another). While experts surveyed in advance predicted that the two would be substitutes, we instead find they are complements: each intervention enhances the other’s impact on learning. The combination of simple teaching and incentive treatments raises COVID-19 knowledge by 0.5 standard deviations.

"The Value of Political Connections for Firms: The Case of Outside Directors in China."[PDF]

  • Abstract: Inviting a government official to sit on the board is a commonly used strategy for firms seeking to become politically connected. This paper estimates the value of this type of political connection with a nationwide, clearly-targeted policy shock in China. In October 2013, the central government announced a new policy restricting government officials from working in firms. Firms with government-official outside directors were affected. We find that government-official outside directors do add to firm value: The stock return of affected firms is on average 8 percentage points lower than that of the control firms in the 12 months following the policy change. The variation in treatment effects across firms suggests that firms rely on this type of political connection to different degrees. Several potential working mechanisms are explored.

Work in Progress

“Interventions to Improve Antiretroviral Therapy Adherence in Beira, Mozambique,” with Dean Yang, James Riddell, Arlete Mahumane, and Jared Stolove. [ClinicalTrials.gov Registry] [AEA Registry]

Study instruments: Videos for the informational intervention in Portuguese and Sena, with English transcripts; Protocol for the stigma-relieving intervention

  • Abstract: Many people living with HIV in Sub Sahara Africa failed to adhere to free Anti-retroviral Therapy (ART), the medical treatment for HIV that can stop the virus from progressing and transmitting. This paper seeks to identify the barriers to treatment adherence. We recruit patients that are new on ART from a large health center in Mozambique and randomly provide interventions to assist them in overcoming the limited attention problem, information imperfection, or social stigma concerns. We track the medication possession ratio (MPR) in six months to evaluate the interventions and benchmark their effects against conditional cash transfers. Moreover, to shed light on the spillovers of the interventions, we offer coupons for the participants to refer their partners to get tested. The experiment result will inform us of behavioral patterns of the population that are economically and physically vulnerable. Effective interventions are ready to be scaled up in HIV-treatment facilities in resource-constrained environments.