This article asks which subgroups of the population are affected by the payment of a small cash incentive to respond to a telephone survey with a listed sample. We find that a promised incentive improves response rates primarily amongst those individuals with the longest history of income support receipt. Importantly, these individuals are least likely to respond to the survey in the absence of an incentive. The incentive thus improves both average response rates and acts to equalize response rates across different socio-economic groups, potentially reducing nonresponse bias. Interestingly, the main channel through which the incentive appears to increase response rates is in improving the probability of making contact with individuals in the group with heavy exposure to the income support system. Incentive payments are often used in conjunction with surveys to increase response rates and/or to improve data quality. In this article, we examine whether the effect of a promised incentive, paid upon survey completion, is related to the socio-economic status of respondents. Specifically, we examine whether a past history of income support receipt is correlated with refusal rates and response rates in a telephone survey with a listed sample. There is a large literature using randomized experiments to assess the impact of incentives on response rates. Most of it is based on mail-out surveys, though a number of studies have looked at incentives in telephone and face-to-face surveys. Both monetary and nonmonetary incentives have been assessed. Church (1993) and Singer et al. (1999) discuss the literature and conclude, generally, that incentives raise response rates, that prepaid incentives are better than incentives which are paid only upon survey completion, and that monetary incentives are more effective at increasing response rates and data quality than gifts or lotteries. In this article, we approach the question from a slightly different angle. Incentives may increase response rates, but do they do so in a uniform way across all socio-economic groups? Using detailed administrative data about the income support receipt of individuals (and their families) from 1993 to 2006, we examine whether the intensity and recentness of