Kurzon posted:

In the novel Starship Troopers by Robert Heinlein, only veterans are allowed to vote. Heinlein believed that veterans would vote more wisely than non-veterans because they understand discipline and sacrifice, which would lead to better governance. But selectorate theory tells me that this would be a terrible idea.

Only 7% of Americans are veterans and therefore only 7% of the American population would have a vote in Heinlein's Utopia. Since voter turnout in elections is never 100% and a candidate needs a majority of the vote to win, you're talking about presidents winning elections with just 1 or 2% of the population's support. This is what political scientists call a small-coalition regime. In a small-coalition regime, the ruler is incentivized to run a regime oriented towards private rewards. He looks after the interests of that 2% at the expense of everybody else, because he only needs that 2% of people supporting him to stay in power. This will lead to a neglect of public goods. The country will have worse roads, worse education systems, worse healthcare, etc. The people will actually be worse off.

What's more, the veterans themselves won't have it so good either. A feature of small-coalition regimes is that the members of the coalition are always looking to expel members and reduce the size of the coalition, so that the surviving members can have larger fractions of the pie for themselves. So what I imagine would happen is that, over time, the ruler would pass laws narrowing what "veteran" means. He might pass laws saying that only veterans who served a minimum number of years can vote. Or maybe only veterans above a certain rank (eg anyone below captain cannot vote). Or maybe only veterans who served in combat roles. Whatever, the idea is to reduce the number of people who are eligible to vote, thereby reducing the size of the winning coalition. The smaller the coalition, the easier it is for the ruler to hold on to power.

What Heinlein's Utopia will be is what Bruce Bueno de Mesquita calls a junta regime. Small coalition, small selectorate. These kinds of regimes are very unstable. Junta leaders face coup d'etats far more often than dictators or democratic leaders.