Should we expect equity valuations to rise as more people across the globe enter the market?
So, wouldn't a global expansion of the middle class cause more people to invest in global markets and drive up stock valuations forever?
Not all middle classes are created equal.
In mainland China, the currency is not convertible and the citizens cannot invest outside of China. Also, foreigners cannot invest in the Chinese stock market. So, there is little chance of those hundreds of millions of newly minted middle class entrants participating in the world stock market.
In India, I believe that the preferred middle class investment is gold. And, from what I've heard about business practices there, I believe that to be a wise decision by millions of Indians.