Of course GDP is an arbitrary abstraction, it's literally derived from arbitrary systems of measurement, i.e. why soviet had mps system and west had sna, and each get to decide what to value and how much... arbitrarily... and even when they calculate, a lot of it is guestimate because no one has perfect or even good data, especially 80 years ago in developing countries.
> starvation or the lack thereof is a strong indication of GDP
No that's just an indicator that some cohort starved due to distribution failure. And to be blunt... that cohort was rural / peasants doing mostly subsistence agriculture tier production that do not count much towards GDP. An urban worker in industry can generate 10x GDP surplus than farmers in a commune.
Hence starvation (mostly in rural) has disproportionately less GDP weight vs urban worker productivity. An economy losing millions of peasants while still modernizing/industrializing can easily maintain higher total GDP than peaceful agrarian society. AKA CCP speed running first 5 year plan post WW2 raised the GDP floor so much that they can unalive 10s of millions of peasants and still have higher GDP vs pre/post war which, was incidentally also not peaceful agrarian society, but even messier interregnum shitshow with significantly shit state capacity than relatively unified postwar PRC under CCP. Republican Era KMT (during anarchy/civil war) simply couldn't organize fragmented China to be as productive as PRC under CCP, who can lose millions of peasants with marginal productivity of labour near zero and still do massively better in gdp/economic terms.
Between 1954 and 1959, China supplied 160,000 tons of tungsten ore, 110,000 tons of copper, 30,000 tons of antimony, and 90,000 tons of rubber to the Soviet Union. That’s how they repaid a loan not through industrial production because their economy wasn’t producing significant high value output from raw materials, they couldn’t even smelt ore efficiently.
Re-education camps don’t generate value. They didn’t have a surplus of urban workers instead Mow just destroyed the economy. Killing off the educated doctors etc isn’t a free action, it has negative consequences.
China literally had net migration out of cities, so no this wasn’t over investment in industry or a distribution issue this was just abject failure and total economic collapse. Total Anarchy would have been better for the economy than Mao.