In that case why would you ever short stocks, because why would anyone sell their stocks for zero yielding cash?
This is a serious question. If you were a pension fund, and you see cash at negative rates and SPX at 2% dividend yield, which would you buy? Yes, you think the market might crash like 2008, but will anyone want to bet that the market is higher 20 years from now anyway? In that case, SPX will return 2%+capital gain %.
