In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Q: In economics , crowding out happens when the government starts buying or selling more stuff in the market .
A: 
In economics , crowding out is a phenomenon that occurs when increased government involvement in a sector of the market economy substantially affects the remainder of the market , either on the supply or demand side of the market .