The Democratic Party of Japan (DPJ) came to power in 2009 promising significant transportation sector reform, but it has struggled to implement its proposals. Phillip Y. Lipscy argues that the DPJ's initiatives faltered due to the legacy of “efficiency clientelism.” Historically, Japanese transportation policy combined two imperatives: (1) encourage efficiency by raising the cost of energy-inefficient transportation, and (2) redistribute benefits to supporters of the incumbent Liberal Democratic Party (LDP). Because of the legacy of efficiency clientelism, DPJ campaign pledges—designed to appeal broadly to the general public by reducing transportation costs—ran up against the prospect of sharp declines in revenues and energy efficiency. Efficiency clientelism was well suited to political realities in Japan prior to the 1990s, but recent developments have undercut its viability. This raises profound questions about the sustainability of Japan's energy efficiency achievements.