Which is a better measure of GDP? Nominal or PPP? GDP is the total market value of goods and services produced in a country. But everything is cheaper in China, so wouldn't nominal GDP be a deflated measure of China's GDP? China's true GDP is measured when you bring everything produced in China up to the price they would be if they were in a Western country (PPP). So in practical terms China would have by far the largest economy in the world. Is this correct?
China's nominal GDP will be in Yuan, as that is what 99% of transactions are completed in and presented nominally to the central bank. But that also makes impossible to compare with non Yuan using economies. PPP is an attempt to normalize the conversion of an entire economy's activity into another currency, mainly for comparative purposes, if 2 areas use different currencies.
PPP is needed to normalize calculations of huge currency conversions, because exchange rates do not apply to vast economic sums. Were you to try and convert a billion dollars to yuan, there is not a single entity in China that will give you the conversion at airport exchange rates. They would take a very hefty extra sum. PPP is to try and offset this phenomenon, to get a picture of comparable economic statistics between 2 different currency using countries.
They are in the end the exact same measure.
China is leading in GDP but not by a vast amount. GDP is the least charitable measure for China because it's based a lot on empty back and forth transactions. GDP is (out of non crackpot measures) the one economic measure where US comes the closest to China out of all.
Consider that a private road that costs 50 million $ and brings in 5 millions $ per annum in tolls will in 10 years generate 100 million $ GDP while a 50 million $ public road with no taxes generates just 50 million as a 1 and done deal.