A somewhat different version of pp. 18-21 appeared as “The Law of Shrinking Support: Implications for Cuba,” in Cuban Affairs, 2014, 9, 3. Much of the remainder, in abridged form, appears in PS: Political Science and Politics, 2015 (July) 48, 3, pp 415-419. under the title, “Five Laws of Politics.” The data file has been expanded since that article was accepted for publication and some errors corrected, so the estimates in table 2 are slightly different from the published version.
Political scientists tend to shy away from claiming that there are laws of politics. This diffidence is unwarranted. Here, I present five empirical laws of politics. By a “law” of politics I mean an empirical regularity that is invariant, or almost invariant, that is descriptive of intrinsic properties of politics, democracy, and the state. The laws, four spanning democracies and autocracies, and one setting a boundary between the two regime types, are drawn from data on 455 elections in 27 democracies, 15 from the Ibero-America (Latin America plus Spain and Portugal), and most of the rest from North America, Europe, and the Pacific Rim (the OECD countries), plus 112 ritualistic "elections" and referendums in 15 dictatorships. Law #1. The law of minority rule. All governments are minority governments. This is a given in dictatorships, but even in democracies parties capture or retain the presidency or the parliament with the votes of a minority of the “selectorate” (registered or eligible voters). In democracies, average turnout is about 75% and the mean incumbent share of the vote is around 40%. Therefore, the average “winning coalition” averages 30%. Law #2. The law of incumbent advantage. In democracies, on average incumbents are reelected more than half the time. Law #3. The law of shrinking support. On average, incumbents lose between 3 and 8 percent points per term, the former representing the "cost of governing" in the OECD region, the latter in Ibero-America. Their illusions of unanimity and perpetual power notwithstanding, dictatorships are not exempt from this law, as evidence drawn from transition elections in autocracies from several continents, cultures, and region of the world attest. Formerly ruling parties crashed, their share of the vote plummeting from the 90-99% they used to claim in single party "elections" to as low as the single digits or low teens. Law #4. The law of 60 percent. In democracies, it is rare for incumbents to win more than 60 percent of the vote, and it never happens twice within the same spell in office. The average maximum incumbent share of the vote across all democracies is 53%, the one variable on which there is no difference between regions. This law serves as a boundary separating all democracies from most dictatorships. Law #5. The law of alternation or shared power. In democracies, control of the government alternates between political parties or coalitions of parties. This is because no party is capable to encompassing the totality of the values and interests of any society. As well as presenting the data that demonstrate these patterns, I place these laws in the context of related scholarly literature, and offer possible explanations for the laws in light of it.