Automobile technology and tradeoffs: How does automobile footprint affect its fuel economy?

We estimate the tradeoff between fuel economy and other automobile attributes, e.g., size and horsepower. We specifically focus on the relationship between fuel economy and vehicle footprint (vehicle width by length). We use automobile specifications data for all car models sold in the U.S. market from 2005 to 2014. Results indicate a positive relationship between footprint and fuel economy controlling for other vehicle attributes. The results have implications for the current footprint-based CAFE standard that treats larger cars more favorably, creating incentives for carmakers to substitute across models.