Health worker shortages are straining healthcare systems worldwide, yet there is limited causal evidence on how to recruit healthcare workers across national borders. In collaboration with Danish healthcare providers, we randomly assign 110,000 European nurses to receive one of 10 different digital messages (or no message), encouraging them to apply for a nursing job in Denmark. We selected interventions using an approach we call “community-led intervention design” (CID) that systematically balances academics’, practitioners’, and healthcare workers’ expertise. Contrary to expert predictions and prevailing policy guidance, messages highlighting pay decreased overall engagement by 7.7% (1.7 percentage points), positive responses by 6.3% (1.4 pp), and applications by 19.0% (0.15 pp) compared to baseline. Messages emphasizing social support and job benefits outperformed pay messages, increasing engagement by 8.1% (1.67 pp) and 9.6% (1.97 pp) respectively. Evidence from an additional online experiment (N = 1,799) suggests that highlighting pay may reduce credibility and signal a less desirable job in dimensions such as work-life balance or prosociality. This megastudy has far-reaching implications for international labor market decision-making, healthcare workforce policy, and hypothesis generation in behavioral science.
