In this paper I apply the nonparametric methods proposed by Quah to data on US state relative income levels. In contrast to Quah’s results using cross-country data I find no evidence of polarization in the cross-state income distribution. The long-run density implied by the estimates is strongly unimodal. This finding is consistent with the results of previous analyses of convergence in state income levels using other methods. 2000 Elsevier Science S.A. All rights reserved.