I. Shifts of industry curves

Per unit and lump sum in a competitive industry

I. Shifts of industry curves

Industry supply^SR (Σ SRMC^-1) - change in MC^SR (approximately parallel upward shift in case of per unit tax or non-parallel ambiguous shift due to an increase in price of variable factor) OR exogenous initial change in the number of firms (more firms=flatter; less firms=steeper)

Σ LRMC^-1 - change in MC^LR (parallel upward shift in case of per unit tax or non-parallel ambiguous shift due to an increase in price of any factor) (approximately parallel) OR change in the number of firms due to the losses/profits (steeper/flatter)

Industry supply^LR - exogenous change in minAC^LR (not due to the ICI, DCI). If minAC^LR and MC^LR changes due to the cost industry= movement along Industry supply^LR

II. Per unit tax/subsidy

;

t is a vertical distance between: ; ;