Aggregated data on credit supply may not show these reallocations of markets shares across institutions – and micro-econometric studies that focus on average effects may not reveal the effects of policy measures either. 1. Policy evaluation requires cross-country comparisons. Policy evaluation is about the identification of causal effects.
This, in turn, requires disentangling the effects of policies, of micro-level drivers, and of country-specific institutional factors. Disaggregation is important to isolate micro-level factors. At the same time, datasets from different countries are needed to isolate frictions and constraints that are driven by country-specific factors and institutions.