Why Not Index the World?

I understand the political reasons why the Clinton’s liquidated millions of dollars worth of stock holdings in their blind trust.

But it seems to me there is a better way for all candidates to arrange their stock and bond portfolios. Why not just index the world markets? That way, they own a piece of the private economy around the world. It’s a low fee, broadly diversified portfolio and it eliminates many conflicts of interest. In fact, public figures could just abandon the whole blind trust idea and openly embrace indexing. Good disclosure and good investing can co-exist.