Earlier this month, Chile completed an overhaul of its system for electing legislators. Under the old system, unique in the world, every member of the Chamber of Deputies and the Senate was elected from a two-member district. Parties or coalitions put two-member lists on the ballot. If the first-place list in a district won more than twice the votes of the second-place list, both its nominees were elected; otherwise, the top candidate from each list went to Valparaiso, the seat of Chile’s Congress.
Under the new system, there will be fewer districts with more seats. The Chamber will have 28 districts with between three and eight seats each; the Senate will have fifteen districts, some still with only two seats, but most with three or five. The overall result is that while the past ideological biases have been removed, there is still no vote equality across regions and districts.
The old system was widely criticized, mainly on two counts—that the two-seat districts favored the second-place coalition, and that the districts in both chambers were severely malapportioned. Malapportionment is the disjuncture between the share of population in a district and its share of seats. In federal systems where every state or region gets equal representation, upper chambers are often malapportioned. (Think about California and Rhode Island.) But lower chamber representation generally maps much more closely to population. Under Chile’s pre-reform system, both chambers were malapportioned—and its Senate districts did not even map straight onto its fifteen subnational regions.
The consensus among observers of Chilean politics was that the system was conceived in sin. It was famously engineered in the late 1980s by the outgoing military regime of General Augusto Pinochet, and fine-tuned with the results of Chile’s 1988 plebiscite in mind. The plebiscite had shown that the left would out-vote the right (but not by two-to one), so two-member districts would lead to a lot of even splits. And the right was relatively stronger in the countryside than the cities, so malapportionment favoring rural areas would further amplify rightist votes.
This year’s reform presents an opportunity to reexamine the fairness of the system.
The two-member districts are largely gone. Only ten of fifty senators, and no deputies, will be elected in binominales. The larger districts will reduce distortions between support within a district and the share of seats won. But what about fairness across districts?
The reform reduced malapportionment somewhat in the Chamber of Deputies but not at all in the Senate. The Senate will remain the ninth most malapportioned upper chamber in the world, and the Chamber the eleventh most malapportioned lower chamber. Malapportionment violates the principle of one person, one vote. Deviations from that principle should require a compelling justification.
The Chilean Senate’s new districts conform to the country’s fifteen regions, but the distribution of seats is not uniform among them, as in Argentina or the United States. So the explanation cannot be the standard federalist one, that every region warrants equal representation, and Santiago’s seven million residents, with the same representation as Temuco’s 900,000, have every reason to cry foul.
The overall disjuncture between population and representation across Chamber districts is less extreme, but more puzzling in the particulars. Fully a quarter of the districts were awarded fewer seats than corresponding districts that have smaller populations. It is not clear why that should ever be so.
The better news is that there is no evidence that all this malapportionment will favor one side or another in future elections. Based on election results over the past fifteen years, I calculated the ideological preference of every Chilean district – Chamber and Senate, pre-reform and post-reform—on a left-right scale. I then plotted the ideology of each district against how well it did in the apportionment sweepstakes—that is, whether it gets more deputies or senators than its population share, or fewer.
There is no relationship between over-representation and ideological preferences in any of the analyses. Malapportionment might have helped the right in the first post-transition elections, but by the 2000s any advantage had dissipated, in both chambers. And based on past election results, the new districts show no signs of systematic bias toward either the left or the right.
Overall, the Chilean reform should be cheered. The larger districts will reduce barriers to entry and allow Chilean voters, who have grown disaffected in recent years, to inject new blood into the legislature if they choose. And the distribution of seats should map more closely onto electoral support than in the past. The remaining malapportionment is a flaw in the system, but it would be easy to remedy using practices well established among other democracies. For now, at least the playing field is not tilted toward one ideological camp or the other.
John M. Carey is the John Wentworth Professor in the Social Sciences at Dartmouth College in Hanover, New Hampshire.