Note: Wage/Price Spiral is not an option.
It seems they were saying that both costs (wages) and profits were going up, so it is both rather than either/or.
Also, in their discussion of the post-WW2 inflation they didn’t mention the impact of lifting several years of price and wage controls. In addition to the unfrozen prices, labor was free to go on strike. The great strike wave of 1945-46 was the largest in US history. Wiki tells us that 4.3 million workers went on strike.
DB2
The US labor force was only 60 million in 1946, so the 4.3 would be the equivalent 12 million on strike today. Talk about supply chain disruptions…
https://www.jstor.org/stable/41818216
DB2