1.the keynesian aemodel is a basic representation of the economy in a situation where, for whatever reason, prices don’t change. a.show, in an aediagram, the change in equilibrium yfrom a given increase inautonomous expenditure. (6 points)b. this simple keynesian result relies on prices not changing when yincreases. one reason prices wouldn't change is that input costs don't change. explain why an increase in gdp might not lead to increased costs for producers. hint: the economy is operating inside the ppf.