The 2008 U.S. Auto Market Collapse

New vehicle sales in the U.S. fell nearly 40 percent during the past recession, causing significant job losses and unprecedented government interventions in the auto industry. This paper explores three potential explanations for this decline: increasing oil prices, falling home values, and falling household income expectations. First, we use the historical macroeconomic relationship between oil prices and vehicle sales to show that the oil price spike explains roughly 15 percent of the auto sales decline between 2007 and 2009. Second, we establish that declining home values explain only a small portion of the observed reduction in household new vehicle sales. Using a county-level panel from the episode, we find (1) a one-dollar fall in home values reduced household new vehicle spending by 0.5 to 0.7 cents and overall new vehicle spending by 0.9 to 1.2 cents and (2) falling home values explain between 16 and 19 percent of the overall new vehicle spending decline. Next, examining state-level data for 1997-2016, we find (3) the short-run responses of new vehicle consumption to home value changes are larger in the 2005-2011 period relative to other years, but at longer horizons (e.g. 5 years), the responses are similar across the two sub-periods and (4) the service flow from vehicles, as measured by miles traveled, responds very little to house price shocks. We also detail the sources of the differences between our findings (1) and (2) from existing research. Third, we establish that declining current and expected future income expectations potentially played an important role in the auto market's collapse. We build a permanent income model augmented to include infrequent repeated car buying. Our calibrated model matches the pre-recession distribution of auto vintages and the liquid-wealth-to-income ratio, and exhibits a large vehicle sales decline in response to a mild decline in expected permanent income due to a transitory slowdown in income growth. In response to the shock, households delay replacing existing vehicles, allowing them to smooth the effects of the income shock without significantly adjusting the service flow from their vehicles. Augmenting our model with a richer set of household expectations allows us to match 65 percent of the overall new vehicle spending decline (i.e. roughly the portion of the decline not explained by oil prices and falling home values). Combining our negative results regarding housing wealth and oil prices with our positive model-based findings, we interpret the auto market collapse as consistent with existing permanent income based approaches to durable goods purchases (e.g., Leahy and Zeira (2005)).