What was the main cause of the increased productivity in the 1950s?

The main cause of the increased productivity in the 1950s was technological advancement.

In the 1950s and 1960s the productivity of average work was rising  as a result of technological advancement and consequently, American citizens enjoyed a higher standard of living than any other nation. During the 1950s there was a boom time for electric gadgets. Technology allowed to create products on order to help improve lives of consumers in the wake of world war II.

a, both were musicians during the jazz age

b)

it created free trade throughout the colonial territories.