If the cause was, "the cotton gin cleaned cotton much faster," what was the effect?

The effect was that way before cotton gins were invented, slaves needed to clean cottons by hand, and a cotton gin cleans a cotton perfectly and much more faster than a slave cleaning the cotton and the cotton gin could clean more cottons at once than a slave cleaning cottons one by one.

john maynard keynes developed new economic theories in response to the stock market crash of 1929. great depression of the 1930s. first and second world wars. economic boom of the 1950s.

explanation: j