Earlier quoted context omitted.
PPP matters on an individual level, but not at all on a national level. GDP at market exchange rates is what actually matters in terms of what a country can accomplish on the world stage. And even on an individual level, PPP struggles with accuracy, because things are only ever roughly equivalent. There's a reason why so many individual people are trying to move from China and India to the US and EU, despite all the…
Wrong. People move from China to India despite the higher prices in America precisely because the increase in wages is more than enough to offset the higher prices.
But the point stands that market-exchange GDP matters more when it comes to comparing the relative strength of countries, rather than individuals, since it endows the government with greater purchasing strength. An era of trade wars might test this theory, but the ramifications of absolute isolationism would be far more complex than that.