 Finally, more recently, when comparing the impact of cash and in-kind grants on the profitability of microenterprises in urban Ghana, McKenzie, Woodruff, Marcel Fafchamps, and Simon Quinn found a "flypaper effect" whereby - unlike cash - capital coming directly into the business "sticks" there, though neither type of grants has an impact on enterprise profitability when provided to female subsistence entrepreneurs.A third area of McKenzie's research has focused on methodological issues across a range of topics, including the issue of endogeneity regarding migration decisions for the measurement of migration's impact (with Marcin Sasin),, the measurement of inequality with household asset indicators through PCA and bootstrapping, the measurement of earnings mobility through dynamic pseudo-panel methods (with Francisca Antman), the superiority of pair-wise matching and stratification over other randomization methods in small samples or for very persistent outcome variables, and the possibility of measuring subjective expectations in developing countries through probabilistic questions (with Adeline Delavande and Xavier Giné).Further important work by McKenzie includes