Scott Alexander explores the Median Voter Theorem, its limitations in real politics, and why recent US elections have been surprisingly close despite these complications.
Longer summary
This post explores the Median Voter Theorem and its application in real-world politics. Scott first explains the theorem, which states that rational candidates will converge on the position of the median voter. He then discusses three reasons why this doesn't perfectly describe reality: primary elections, voter turnout, and party goals. Despite these complications, Scott notes that recent US elections have been surprisingly close to 50-50, suggesting some validity to the theorem. He explores how parties might target different median voters for different elections (House, Senate, Presidency) and considers how parties might adjust their positions in response to structural advantages. The post ends with questions about how quickly and effectively parties can shift their positions in response to changing political landscapes.
Shorter summary