Seasonal migration programs are widely used around the world, yet there is little evidence as to their development impacts. A multi-year prospective evaluation of New Zealand's Recognised Seasonal Employer (RSE) worker program was designed to measure the impact of participating in this program on households in Tonga and Vanuatu. New Zealand launched the Recognised Seasonal Employer (RSE) program in 2007. The program set up a new migration category to allow workers to be recruited for seasonal work in New Zealand's horticulture and viticulture industries. Between 2007 and 2010 researchers from the World Bank and New Zealand's University of Waikato conducted four waves of surveys in Tonga and Vanuatu providing 70 percent of the Pacific Island workers in the RSE. In each country the team surveyed 450 households drawn from about 50 communities, including households supplying workers, households with RSE applicants who were not recruited and non-applicant households. The baseline survey was conducted before workers left to work in New Zealand in the first season. The workers were re-interviewed 6, 12 and 24 months later. Using the baseline data and institutional knowledge of how recruitment for the program occurred, the impact evaluation team used propensity-score matching to identify an appropriate set of households to act as a comparison group for the households participating in the RSE, and then used panel difference-in-differences and fixed effects estimation to assess the impacts of the RSE on household income, consumption, durable assets and subjective well-being. The baseline and three follow-up rounds datasets are documented here.