The Drug War Is Hard to Win Because Seller Revenues Increase with Greater Enforcement Without drug prohi bition, the market equilibrium is at point a with seller revenues given by the blue area. Prohibition raises the costs of supply, pushing up the supply curve and moving the equilibrium to point b. At point b, seller revenues are the larger green area. Prohibition in this graph reduces the quantity of drugs consumed a little, from QNo pro to QPro, but it raises seller revenues by a lot.