The world is going through a slow transition from coal and oil to renewables, mainly solar and wind power, as its main sources of energy. This is partly due to the much higher price of oil and partly to cost-cutting technological breakthroughs and greater practical experience using solar and wind power. But those factors don’t explain the whole story, since different economies have adopted renewable technologies at very different speeds. Aklin and Urpelainen persuasively argue that a combination of domestic politics and external shocks, such as the OPEC oil price hikes of the mid-1970s and the 1986 Chernobyl nuclear disaster, has led to different levels of support for renewables from country to country. The book usefully documents the most important shocks and explains how domestic policies have changed since the 1970s, focusing on Denmark, Germany, and the United States.