In this recent entry, Eliezer discussed what might be called the "pork-barrel paradox" in politics, that even when there is public support for reducing the size of government, the political constituency for individual programs can be strong enough to keep them all going. He also points out that the occupations represented in Congress don’t match the country at large, and maybe don’t match what we really need. (To briefly quote myself, I’m willing to believe that the country’s 890,000 lawyers are being overrepresented, but what about the 114,000 biologists? A few of these in Congress might advance the understanding of public health. And then there are the 290,000 civil engineers–I’d like to have a few of them around also. I’d also like some of the 280,000 child care workers and 620,000 pre-K and kindegarten teachers to give their insight on deliberations on family policy. And the 1.1 million police officers and 340,000 prison guards will have their own perspectives on justice issues.)
Anyway, this reminded me of some other biases that are inherent in our political system:
Even if our political system is working perfectly as designed, not all individuals and groups will be treated equally. Kids don’t get to vote and can’t hold political office, even though they are nominally represented in the government. Voters in small states are vastly overrepresented in the U.S. Senate. Votes for minor parties are generally wasted (at least in their direct effects), and proportional representation creates other problems (that’s a story for a different day). And as long as campaigns need money, rich people and better-funded groups can expect disproportionate representation of their political views.
Looking at representation in terms of decisive votes creates other paradoxes. If you want politicians to fight for your vote, then elections have to be close (or at least potentially close), but when an important election actually is close (as in the 2000 Presidential election), half the people are going to feel unrepresented.
Two other systematic biases that have been studied by political scientists relate to the tyranny of the majority and the median voter. Majority rule has always been considered dangerous since, for example, 51% of the people could get together and vote to tax the other 49% out of existence (as conservatives were worried about during the New Deal in the 1930s). The founders of the U.S. Constitution created various checks and balances to slow this down, but it is still somewhat of a mystery why the majority in a democratic system is not more tyrannical. Perhaps one reason is that most people do not trust politicians enough to lend them this power.
The median voter rule was formulated by Harold Hotelling as an application of a theorem in economics and was developed further in a book by Anthony Downs in 1957. The basic idea is that any voter will choose the candidate who is ideologically closest to him or her. Then all the voters to the left of the D position will go for the Democrat, all the voters to the right of R will side with the Republican, and the voters in the middle will go for whichever is closest.
In this scenario, the Democrat will gain votes by moving to the right–he or she will still get all the voters on the left and will also gain some votes in the center. Similarly, the Republican should move to the left. Ultimately, the only stable position for the candidates is for them both to be at the position of the median voter (labeled M in Figure 2). If either candidate deviates from this position, the other can move to the median and get more votes. It’s not that there are no voters at the extreme, it’s just that these extreme voters have nowhere else to go. (All the minor-party candidates together typically get less than 5\% of the vote.)
Getting back to representation, this theory suggests that the median voter is strongly represented by the political system, whereas voters away from the center have no representation. This translates into less representation for groups such as African Americans and other ethnic minorities whose political views are far from the center.
In real life, however, Democrats and Republicans do not occupy the same point at the center of the political spectrum, and so the median voter rule does not tell the whole story. The differences between parties can be studied in various ways; for example, when the 435 Congressmembers were ranked from left-wing (negative scores) to right-wing (positive scores) based on their roll-call votes (Poole and Rosenthal, 1997), you find that Democratic and Republican politicians differ a lot in their ideologies (as measured by their actions in Congress), even after controlling for the political slants of their districts. There are many reasons for this, including competition in primary elections, the need of politicians to secure funds and backing from interest groups closer to the political extremes, and party discipline within Congress. The point here is that the median voter rule gives some insights into political representation, but it is not completely borne out by the data.
P.S. Unlike Eliezer, I’m not so worried about voters identifying with the Democrats and Republicans as sports teams. I take the standard political science line on this, which is that somebody has to do the organizational work of representative politics, and that’s what political parties are for.