This paper compares the quality and use of regulatory analysis accompanying economically significant regulations proposed by US executive branch agencies in 2008, 2009, and 2010. We find that the quality of regulatory analysis is generally low, but varies widely. Budget regulations, which define how the federal government will spend money or collect revenues, have much lower-quality analysis than other regulations. The Bush administration's “midnight” regulations finalized between Election Day and Inauguration Day, along with other regulations left for the Obama administration to finalize, tended to have lower-quality analysis. Most differences between the Bush and Obama administrations depend on agencies' policy preferences. More conservative agencies tended to produce better analysis in the Obama administration, and more liberal agencies tended to do so in the Bush administration. This suggests that agencies more central to an administration's policy priorities do not have to produce as good an analysis to get their regulations promulgated.