Taxes and subsidies have an effect on market supply and demand curves. If a tax is paid per output by suppliers, then the supply curve will shift upwards by an amount equal to the tax per unit. Given an upward sloping demand curve, this will result in an increase in price and a decrease in output. The burden of the tax will be allocated between consumers and producers depending on the price elasticity of the demand curve. If the demand curve is relatively inelastic, the price paid by consumers will rise by a relatively large amount and the quantity produced will not fall much. Consumers will bear a relatively high proportion of the total tax, as represented by the increased price per unit. If the demand curve is relatively elastic, the price paid by consumers will not rise much but the quantity produced will drop substantially. Since producer revenue is the price paid by consumers less the tax per unit sold, producer revenue will fall by a relatively high amount (the loss of revenue due to the tax will not be offset very much by the small price increase) and producers will bear a high proportion of the total tax.