Definition of PES
Responsiveness of quantity supplied after a change in price
PES formula
% change in qty. supplied / % change in price
Perfectly Inelastic supply
PES = 0
Change in price causes no change in qty. supplied
Inelastic supply
PES > 0 but < 1
A change in price will cause a less than proportionate change in quantity supplied
Elastic supply
PES > 1
A change in price will cause a more than proportionate change in quantity supplied
Unitary elastic supply
PES = 1
Perfectly elastic supply
PES = ∞
Change in price causes NO supply at all
Factors that influence PES? (6)