Actually, did a Nobel Laureate economist just say this?
It is not even true that higher corporate tax rates would necessarily significantly decrease investment. As Apple has shown, it can finance anything it wants to with debt – including paying dividends, another ploy to avoid paying their fair share of taxes. But interest payments are tax deductible – which means that to the extent that investment is debt-financed, the cost of capital and returns are both changed commensurately, with no adverse effect on investment.
Interest income is taxed at the level of the recipient. Thus the tax charged does indeed change the willingness of the lender to lend. Investment is indeed affected by such taxation therefore.
That interest is untaxed at the corporate level might change the actions of the corporate: but that it is taxed elsewhere means that there is still a change in the amount of investment.
Seriouly, how can anyone say that the imposition of a tax doesn\’t change behaviour? Let alone a Nobel Laureate?