My paper for this special issue (Ruhs, 2010), which builds on analysis in a previous paper with Phil Martin (Ruhs and Martin, 2008), suggests the hypothesis of a trade‐off (i.e. an inverse relationship) between the number and some of the socio‐economic rights of low‐skilled migrant workers admitted to high‐income countries. Ruhs (2010) discusses the economic factors and mechanisms that may give rise to such a trade‐off and presents several brief case studies that, I argue, provide some illustrative empirical support for the existence of a trade‐off. As I make clear in the conclusion, there is ‘clearly a need for more systematic empirical research that includes a larger number of countries and that investigates alternative explanations of the relationship between the number and rights of low‐skilled migrant workers admitted to high‐income countries’ (Ruhs, 2010, p. 276) The paper by Cummins and Rodríguez (C&R, 2010) aims to provide this systematic empirical analysis. C&R conclude that their statistical tests ‘do not on the whole support the existence of a numbers versus rights trade‐off in immigration policy’ (2010, p. 283). The authors emphasize that the measurement of migrant rights and immigration policies is still at a nascent stage and that future assessments and better data ‘could, in turn, lead us to re‐evaluate the conclusions presented in this paper’ (p. 298). I consider the analysis by C&R unconvincing as a systematic empirical test of the numbers versus rights hypothesis for two reasons, namely: their conceptualization and measurement of the number of migrant workers in the context of this debate, and the indices used to measure the rights of migrant workers. I conclude with an outline of the systematic empirical analysis needed to advance the debate.