In the paper by Hughes, Knittel, and Sperling, they “estimate and compare price and income elasticities of gasoline demand in two periods, from November 1975 through November 1980 and from March 2001 through March 2006” (4). They use data such as average per capita gas consumption in the U.S., personal disposable income, and average U.S. retail prices. Hughes, Knittel, and Sperling use the double-log functional form for this particular study. Additionally, they use alternate model specifications to “test the robustness of the price and income elasticity estimates produced by the basic model” (8). They used two different types of instrumental variables which are: crude oil quality and crude oil production disruptions. Crude oil production disruptions were used for three different countries: Venezuela, Iraq, and the United States. They found that the disruption periods are December 2002-March 2003 for Venezuela, March 2003-November 2003 for Iraq, and September 2005-January 2006 for the United States. Crude oil quality did not produce a significant result, however, oil production disruptions did. They found that from 1975-1980, the short-run price elasticity of gasoline demand is from -0.21 to -0.34, and -0.034 to -0.077 from 2001-2006. From their data, they found that the short-run price elasticity of gasoline demand is more inelastic today than in previous decades. In the short-run, consumers are less responsive to increases in the price of gas. They hypothesize that U.S. consumers are more dependent on cars for daily transportation today than they were 30-40 years ago, and because of this, higher gas prices can’t necessarily stop people from driving. Another hypothesis is that “as incomes have grown, the budget share represented by gasoline consumption has decreased making consumers less sensitive to price increases” (15). In any case, higher gas prices have not