In effect it takes about a third of all companies, because corporate tax rates are about a third of earnings.

Right... you could say that the United States is 33% socialist, based on the tax rates. Is it inherently better for a government to tax corporations instead of owning them? I look at China, which owns 30% of Lenovo and has shares in many Chinese companies and wonder if a combination of taxing and partial state ownership is the way to go.