Original median voter theorem paper, Duncan Black in 1948

Let us suppose that a decision is to be determined by vote of a committee. The members of the committee may meet in a single room, or they may be scattered over an area of the country as are the electors in a parliamentary constituency. Proposals are advanced, we assume, in the form of motions on a particular topic or in favor of one of a number of candidates. We do not inquire into the genesis of the motions but simply assume that given motions have been put forward. In the case of the selection of candidates, we assume that determinate candidates have offered themselves for election and that one is to be chosen by means of voting. For convenience we shall speak as if one of a number of alternative mo- tions, and not candidates, was being selected.

Let there be n members in the committee, where n is odd. We suppose that an ordering of the points on the horizontal axis representing motions exists, rendering the preference curves of all members single-peaked. The points on the horizontal axis corresponding to the members' optimums are named O, 02, 03, . . . , in the order of their occurrence. The middle or median optimum will be the (n + I)/2th, and, in Figure 3, only this median optimum, the one im- mediately above it and the one immediately below it are shown

Anyway, this is really a pedagogic question. How best should we teach politics? Some people advocate that we should disregard the MVT because it is both "obvious" and "false". Setting that contradiction aside, I think the underlying assumption that only theories with perfect data fit should be taught is wrong. By the same logic, physics should not teach Newtownian mechanics because it is wrong relative to quantum mechanics. You can't just give the reader quantum mechanics, you need to start with a theory they can understand then update it.

1. The median voter theorem is just a mathematical conclusion from a set of simple assumptions, it can't be watered up or down. If some set of voters rank proposals on a single axis with single-peaked preferences then the only Condorcet winner will be the median voters ideal point. The key here is that the voters choose the axis on which to rank the proposals. The voters can rank the candidates on any axis, taxes or policies or height. Usually smarter actors rank proposals and candidates on an ideology axis by collapsing issues onto one axis, as a mental heuristic. But if they interpret the axis as "does he run ads where he shoots guns" instead of "does he vote for my tax rate", the gun ads determine the axis not the tax rate. In this case the assumption is that Republican primary voters care a lot about the Trump-support axis.

The two level game papers are cool, but not relevant here.

The MVT is important here because Trumps influence over represenatives is non-linear with his vote share. If Trump loses 20% of his primary influence and loses the median primary voter, he does not lose 20% of his influence, he loses most of his influence.

2. There are better ways to select leaders, but our current leaders choose not to influence them. Our current leaders like the current leader-selection system because they win at it. (See paper)[https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-9248.2005.00514.x?casa_token=R0YSBl-4UKQAAAAA:pwa_9ENFHN8VU9PT50ymM6R1fy57NtdDSW1R7K5aeT8tGXMRvLzwHzkAoFh7di80Lp4mv8b4e8ZnFWg]

Interesting, that's a good point.

That’s good pushback, thank you.

I'll need to edit the piece more deeply, but for now I've added an explanation at the top.

Here are some counter criticisms

1. That is a great summary of the modern critique of the MVT, thanks for sharing. The problem is that it applies to policy outcomes, but the subject is candidate selection. Caplan’s criticism is that voters are irrational at connecting votes to policies and policies to outcomes, which is true. If voters have a simpler utility function like “I want to vote against any anti-Trump candidates”, the median voter will apply very well. If 51% of voters choose to vote against any anti-trump candidates and you are anti-trump, the MVT will still cook your goose. Compare with democratic primaries, where the Bernie faction mobilized 40%, but Bernie does not have 4/5s of Trumps influence at all.

The response concerns me because Berkowitz passes up a great opportunity to explain a fundamental dynamic of the system in question. Imagine asking an economist “why did the price of gasoline increase when supply contracted” and the economist didn’t mention supply and demand curves. Sure it could be a Giffen good with a weird speculative market, but your explanation should start with the theory that explains maximum variation, then move to edge cases.

2. Saying there is no silver bullet is a strong positive claim that Berkowitz doesn’t back up. I’m not all claiming there is definitive evidence that a silver bullet exists. I am simply claiming that we have not seen evidence disproving silver bullets, which Berkowitz claims. I should have made that more clear.

Viz-a-viz populism, if we define populism as “did any populist party form” then yes, there are few patterns. Martin Gurri is probably right that populism emerges from the information environment. But if we define it as populists that cam close to ruling, by getting 20% of the vote share, then we have some patterns. The German Bundestag was stunningly successful at deescalating every issue that the populists could use after 2016, for example (they paid billions to keep refugees out of Europe). Keeping populists out of office can probably be done with electoral engineering, but keeping populist minorities from forming can’t, so depends on goal post definitions.

3. Fair enough, I shouldn’t argue that policy feedback is the definitive reason and Trump not. I'm just concerned that Berkowitz doesn't mention other explanations. Generally I am suspicious that activists will overfit on data to make their issue seem really important.

Democracies did not exist in the premodern world for one main reason; they were bad at war. Revolutions and republics did form in the Medieval period, particularly in capital-intensive trade hubs like Northern Italy and Northern Germany. However, most were quickly crushed under a wave of poorly armed peasant-soldiers from the coercive states next door.

A major reason for democracies rise in the 17th-21st centuries because democracies suddenly became much better at warfare than all other systems, and have maintained this advantage ever since. The first state to create a democratic nation-state and harness it to war was the Dutch in the Dutch revolt, who shocked Europe by defeating the Habsburg Empire. Shortly afterward Britain formed a democracy-nation hybrid who set the standard for military power. All major world wars since have been resounding Democratic victories., from the War of Jenkin's Ear to the Cold War. The main advantages of the democratic system are

• Modern democracies had both large populations and property rights for capital, combining the two great advantages of previous state forms. Some autocracies have greatly improved their ability to accumulate capital to close this gap (Fascist Italy, China, Soviet Union).
• Leaders pay a higher cost for defeat
• Democracies can more credibly issue bonds (democratic advantage has faded over time)
• Democracies rarely have to coup proof (divide and purge the military to prevent coups)

This advantage should be completely irrelevant going forward. China and Russia may democratize, giving the democracies a clean sweep of the security council powers. But the democracies are already at maximum influence in many stable anocracies like Morocco and Jordan.

Hahaha I love hearing someone else say "cluster in polity-space". I use that phrase often but the other political scientists never do. It's an incredibly useful framework for describing correlated variations and side-stepping pointless debates about definition.

That's all spot on. Stable alternative models are rare and poor performing (Belgium, Lebanon, Bosnia, Libya).

The steel man for a democratic long run future: In the long run, the political system that survives longer should dominate. Once democracies pass a production threshold around 10,000 gdppc transitions become extremely rare. The half-life of a rich parliamentary system is really long > 200 years. By comparison autocracies have been unstable so far in all periods.

Selectorate: People who select the leader

Ejectorate: People who don't.

In the Soviet Union, the selectorate was the Politburo Standing Committee. In Egypt and Myanmar the selectorate is a group of generals. In the US the selectorate are voters in swing states.

Thanks for the feedback.

I haven't ported the citations to this format yet, fyi

My professor Hans Noel is featured in the article. Nice.

I have a friend who is making the first two mistakes. They are in a different field from EA but similar totalizing vibe. They rarely apply to jobs that are outside their field-role but which would provide valuable career capital. They are also quite depressed from the long unemployment.

What can I say to help them not make these mistakes?