Retail and wholesale gasoline prices vary over time and across geographic locations due to differences in government policies and other factors that affect demand, costs, and market power. We use a two-equation, reduced-form model to determine the relative importance of these various factors. An increase in the price of crude oil has been virtually the only major factor contributing to a general rise in prices over the last couple of decades. Tax variations and mergers contribute substantially more to geographic price differentials than do price discrimination, cost factors, or pollution controls.

The federal specific gasoline tax falls equally on consumers and wholesalers; whereas state specific taxes fall almost entirely on consumers. The consumer incidence of state taxes is greater in states that use relatively little gasoline.

We apply an incomplete demand system to supermarket scanner data to estimate the effects of a fat tax on dairy products for different demographic groups. We find own-price elasticities of demand are relatively inelastic and vary little across groups. A fat tax may be an effective means to raise revenue, but will not result in a significant reduction in fat consumption. The welfare effects associated with a fat tax are large and vary greatly across demographic groups. These fat taxes are regressive in nature, as the elderly and poor suffer greater welfare losses.

Do milk marketing orders affect various demographic groups differently? To answer this question, we use supermarket scanner data to estimate an incomplete demand system for dairy products. We use these estimates to simulate substitution among dairy products and the welfare impacts of price changes resulting from changes in milk marketing orders for various consumer groups. While we find little difference in own- and cross-price substitution elasticities of demand, the welfare effects of price changes vary substantially across demographic groups, with some losing and others winning from this government program.