In the early 1970s, communist North Korea had the stronger economy of the two Koreas. But North Korea's economy stagnated in the wake of the collapse of the Soviet Union as the regime resisted the shift toward capitalism in the world around it.can't be ridiculed enough, as it reminds us of Cambridge's Joan Robinson's pilgrimage to North Korea which produced an article in Monthly Review in 1964 titled Korean Economic Miracle. In which she predicted that the socialist North would eventually have to absorb the South since the North was so much more productive!
For those too young to remember, Korea was conquered and occupied by Japan in WWII and then divided into two countries from which developed the Korean War of 1950-53. So both Koreas had very low bases from which to measure progress in their economies. Even back then, it was recognized that there was something wrong with Communist statistics, as Pyongang started to withhold information from the world about grain production in 1962 (until 1975).
So any claim that North Korea had a stronger economy in 1970 has to be based on credulously swallowing not only obvious lies, but lies that are over a half century old.