Why do governments compete via tax on corporate earnings?

Tax competition between OECD countries plays out only via reductions in the tax rate on corporate earnings and not via reductions in other taxes. This is the case at present in the United States and the United Kingdom; France is also going to lower its company tax rate. Yet when we compare OECD countries, we see that the most effective tax to reduce (among corporate social contributions, tax on earnings, production tax, total tax on capital income) in terms of boosting employment, investment and potential production is clearly corporate social contributions. So why do governments persist in reducing tax on corporate earnings? The idea is probably that the increase in profits will stimulate investment and employment. But a comparison between OECD countries seems to show that this is the case to some extent with employment but not investment.