Hannah Trachtman

The income elasticity of labor supply is a central parameter of many economic models. We test the response of labor supply and effort to exogenous changes in income using data from a randomized evaluation of a multi-faceted grant program in northern Ghana combined with a bagmaking operation that we implemented. We find strong evidence of a positive “income effect” on labor supply. We argue that simple models with either labor or capital market frictions cannot explain the results, whereas a model that allows for positive physiological or psychological productivity effects from higher income fits with our findings.

We study the drivers of like-minded and low-reliability news-following on social media, and the effectiveness of interventions targeting them. In a five-week field experiment with more than 3,000 U.S. Facebook users, we document the passive nature of participants’ news portfolio formation process and the role of behavioral frictions. The experiment varies whether participants are prompted to re-optimize the portfolio of news pages they follow on Facebook through a user-friendly platform-integrated interface, and whether they receive personalized information about outlet slant and reliability. In contrast to canonical models of news consumption, we find that the re-optimization interface induces large portfolio changes even without new information, while information alone has no effect unless paired with re-optimization. Our interventions produce two main effects: they reduce the slant and increase the reliability of users’ portfolios, thus potentially mitigating negative externalities for democracy, and they move users’ portfolios closer to their stated preferences, mitigating internalities.

Information asymmetries between managers and workers are especially pronounced when workers possess professional expertise. In health care, excessive costs are common, yet directly incentivizing cost-control can produce unintended consequences. We evaluate whether a low-cost, scalable intervention can reduce surgical costs without compromising patient care. In a field experiment, surgeons and nurses randomly receive customized information on typical equipment usage for procedures they perform. The intervention reduces expenditure on targeted disposable equipment by 9–10%, with no adverse effect on clinical outcomes. The effects are driven by surgeons, with evidence suggesting the intervention operated by making choices regarding equipment use salient.

Impact evaluations of behavioral interventions typically focus on target outcomes. Might interventions induce negative spillovers on other behaviors? I run a large field experiment in which individuals receive combinations of messages and incentives promoting two healthy behaviors, meditation and meal logging. I find that the interventions reduce completion rates of the opposite behavior by 19–29%. I find that interventions with larger target effects do not necessarily generate larger negative spillovers, and demonstrate implications for cost-effectiveness analysis. I investigate the mechanisms behind the observed spillovers.

A multi-faceted program comprising a grant of productive assets, training, unconditional cash transfers, coaching, and savings has been found to build sustainable income for those in extreme poverty. We focus on two important questions: whether a mere grant of productive assets would generate similar impacts (it does not), and whether access to a savings account with a deposit collection service would generate similar impacts (it does, but they are short-lived).

If people enjoy giving, then why do they avoid fund-raisers? Partnering with the Salvation Army at Christmastime, we conducted a randomized field experiment placing bell ringers at one or both main entrances to a supermarket, making it easy or difficult to avoid the ask. Additionally, bell ringers either were silent or said “please give.” Making avoidance difficult increased both the rate of giving and donations. Paradoxically, the verbal ask dramatically increased giving but also led to dramatic avoidance. We argue that this illustrates sophisticated awareness of the empathy-altruism link: people avoid empathic stimulation to regulate their giving and guilt.

If being asked to give to charity stimulates an emotional response, like empathy, that makes giving difficult to resist, a natural self-control mechanism might be to avoid being asked in the first place. We replicate a result from a field experiment that points to the role of empathy in giving. We conduct an experiment in a large superstore in which we solicit donations to charity and randomly allow shoppers the opportunity to avoid solicitation by using the other door. We find the rate of avoidance by store entrants to be 8.9%. However, we also find that the avoidance effect disappears in very cold weather, suggesting that avoidance behavior is sensitive to its cost.