I demonstrate that Ai and Norton's (2003) point about cross differences is not relevant for the estimation of the treatment effect in nonlinear "difference-in-differences" models such as probit, logit or tobit, because the cross difference is not equal to the treatment effect, which is the...

We estimate the employment effects of training, intervention works (subsidised employment), and public works programmes in Poland. The analysis is based on retrospective monthly calendar information on the labour force state and active labour market programme (ALMP) participation between January...