Pois é. Tem, realmente, o impacto que ele diz ter? Veja aqui. Artigo interessante, não? Veja alguns trechos da conclusão:
This paper re-evaluates the empirical evidence of a minimum-wage effect on employment. Several meta-regression tests corroborate Card and Krueger’s overall finding of an insignificant employment effect (both practically and statistically) from minimum-wage raises. Recently developed tests for publication selection bias confirm its presence in this area of labour research. The research on minimum-wage effects contains the clear trace of selection for adverse employment effects.
In the minimum wage literature, the magnitude of the publication selection bias is as large or larger, on average, than the underlying reported estimate. Overall, correcting for publication bias would transform a modestly negative average elasticity to a small positive employment elasticity. However, our meta-regression analysis identifies several factors, including structural change, that affect the magnitude of the minimum-wage elasticity. Thus, no single estimate can adequately summarize the minimum wage effect on employment. Rather, estimated employment effects are dependent upon research choices and time. Even under generous assumptions about what might constitute ‘best practice’ in this area of research, little or no evidence of an adverse employment effect remains in the empirical research record, once the effects of publication selection are removed.
É, a coisa não é assim tão simples…