Why does tax competition take place via the taxation of corporate earnings and not via other taxes?

OECD countries engage in tax competition by lowering taxes on corporate earnings , but not via other taxes (direct taxes on households, social contributions of households or companies). This choice is strange, because the only tax which seems to have an impact on the employment rate, the structural unemployment rate and growth is corporate social contributions. A low corporate tax rate does not seem to be associated with any overall structural improvement in a country's economic situation.