Chile’s ongoing constitutional process: 2023 election

Chilean voters selected a new “constitutional council” on 7 May. This renewed process of constitution drafting comes after voters decisively rejected a draft that had been developed by an elected “constitutional convention” in a referendum in September, 2022.

This council consists of 51 elected members (the previous convention had 155). Unlike the previous body, which needed a two thirds vote to submit a draft to the public, this one requires only three fifths. However, it also is bound by a series of principles in a prior agreement among some of Chile’s parties and is supposed to work with a draft created by an expert commission appointed by congress. (Details of the rather complex process at Constitution Net.)

This council was elected via open lists (per the last-linked item), but I do not have the other details of the electoral system. The election result is rather short of being fully representative. The Republican Party won 22 of the 51 seats on only 34.3% of the votes. That’s an advantage ratio (%seats/%votes) of 1.26, which is very much on the high side for a “proportional” system. Two parties that combined for over around 14% of the votes obtained no representation at all and nearly 21% of votes were blank or “invalid.” The Republicans are the party of the 2021 presidential runner-up, José Antonio Kast, who is on the pinochetista far right. Combined with other right-wing parties, the broader right has the three fifths majority needed to approve a draft (“Safe Chile,” which includes the old RN and UDI, won 11).

Another notable difference is this council will have one indigenous representative, elected on 3% of the votes cast for indigenous lists. The previous constitutional convention had 17 indigenous seats elected separately from the 138 general seats. (That 3% this time is over 300,000 votes, whereas the 17 previously represented around 283,000, but total turnout and valid votes were much lower then.)

The previous assembly was evidently well to the left of the median voter (based on the nature of its draft and how badly it was rejected in the referendum). This one would seem to be well to the right of the median (after all, the president, elected in a two-candidate runoff in 2021, heads an alliance that includes the Communist Party). Whether the constraints on the council elected this time will lead to the adoption of a draft acceptable to the public is an open question. In any case, Chile is certainly showing the difficulties inherent in attempting to established a representative process for constitutional replacement.

Chile 2017: Meet your new seat product

As discussed previously, Chile has changed its electoral system for assembly elections (and for senate). The seat product (mean district magnitude times assembly size) was increased substantially. Now that the 2017 Chilean election results are in, did the result come close to the Seat Product Model (SPM) predictions?

The old seat product was 240 (2 x 120). The new seat product is 852.5 (5.5 x 155). This should yield a substantially more fragmented assembly, according to the SPM (see Votes from Seats for details).

I will use the effective number of parties (seats and votes) based on alliances. The reason for this choice is that it is a list PR system, and the electoral system works on the lists, taking their votes in each district and determining each list’s seats. Lists are open, and typically presented by pre-election alliances, and the candidates on a list typically come from different parties. But the question of which parties win the seats is entirely a matter of the intra-list distribution of preference votes (the lists are open), and not an effect of the electoral system’s operation on the entities that it actually processes through seat-allocations formula–the lists. However, I will include the calculation by sub-alliance parties, too, for comparison purposes.  [Click here for an important correction on the intra-list allocation. Nonetheless, the error in the above does not affect any of the calculations in this post.]

The predicted values with the new system, for effective number of seat-winning lists (NS) and effective number of vote-earning lists (NV), given a seat product of 825.5, are:

NS=3.08 (SPM, new system)

NV=3.45 (SPM, new system).

The actual result, by alliance lists, was:



So the Chamber of Deputies is almost exactly as fragmented as the SPM predicts! In the very first election under the new system! The voting result is somewhat more fragmented than expected, but not wide of the mark (about 14%). It is not too surprising that the votes are more off the prediction than the seats; voters have no experience with the new system to draw on. However, the electoral system resulted in an assembly party system (or more accurately, alliance system) fully consisted with its expected “mechanical” effect. The SPM for NS is derived from the constraints of the number of seats in the average district and the total number of seats, whereas the SPM for NV makes a potentially hazardous assumption about how many “pertinent” losers will win substantial votes. We can hardly ask for better adjustment to new rules than what we get in the NS result! (And really, that Nresult is not too shabby, either.)

Now, if we go by sub-alliance parties, the system seems utterly fragmented. We get NS=7.59 and NV=10.60. These results really are meaningless, however, from the standpoint of assessing how the electoral system constrains outcomes. These numbers should be used only if we are specifically interested in the behavior of parties within alliances, but not for more typical inter-party (inter-list) electoral-system analysis. It is a list system, so in systems where lists and “parties” are not the same thing, it is important to use the former.

To put this in context, we should compare the results under the former system. First of all, what was expected from the former system?

NS=2.49 (SPM, old system)

NV=2.90 (SPM, old system).

Here is the table of results, for which I include Np, the effective number of presidential candidates, as well as NV and Ns on both alliance lists and sub-alliance parties.

By alliance By sub-list party
year NS NV NP NS (sub) NV (sub)
1993 1.95 2.24 2.47 4.86 6.55
1997 2.06 2.54 2.47 5.02 6.95
2001 2.03 2.33 2.19 5.94 6.57
2005 2.02 2.36 3.01 5.59 6.58
2009 2.17 2.56 3.07 5.65 7.32
mean 2.05 2.41 2.64 5.41 6.79

We see that the old party (alliance) system was really much more de-fragmented than it should have been, given the electoral system. The party and alliance leaders, and the voters, seem to have enjoyed their newfound relative lack of mechanical constraints in 2017!

Can the SPM also predict NP? In Votes from Seats, we claim that it can. We offer a model that extends form NV  to NP; given that we also claim to be able to predict NV from the seat product (and show that this is possible on a wide range of elections), then we can also connect NP to the seat product. We offer this prediction of NP from the seat product as a counterweight to standard “coattails” arguments that assume presidential candidacies shape assembly fragmentation. Our argument is the reverse: assembly voting, and the electoral system that indirectly constraints it, shapes presidential fragmentation.

There are two caveats, however. The first is that NP is far removed from, and least constrained by, assembly electoral systems, so the fit is not expected to be great (and is not). Second, we saw above that NV in this first Chilean election under the new rules was itself more distant from the prediction than NS was.

Under the old system, we would have predicted Np=2.40, so the actual mean for 1993-2009 was not far off (2.64). Under the new system, the SPM predicts 2.62. In the first round election just held, NP=4.17. That is a good deal more fragmented than expected, and we might not expect future elections to feature such a weak first candidate (37% of the vote). It is unusual to have NP>NV, although in the book we show that Chile is one of the countries where it has happened a few times before. Even the less constraining electoral system did not end this unusual pattern, at least in 2017.

In fact, that the assembly electoral system resulted in the expected value of NS, even though NP was so high, is pretty good evidence that it was not coattails driving the assembly election. Otherwise, Ns should have overshot the prediction to some degree. Yet it did not.

Chilean electoral reform

The electoral reform in Chile has been approved. As is to be expected in such processes, the final version is a bit different than what had been proposed back in 2013 when we first discussed the Chilean electoral reform.

The size of the Chamber of Deputies will be increased from 120 to 155, and the chamber will be redistricted to have 28 districts (currently there are 60). This means a mean magnitude of 5.5; the range will be 3-8. This is a very substantial change from the current system, in which all districts elect just two.

The Senate is also being increased in size from 38 elected members to 50. The fifteen regions will constitute electoral districts, leading to an average district magnitude of 3.3 (range of 2-5).

The D’Hondt method is retained, as are the open lists.

There will be a gender quota concerning nominations: neither men nor women can constitute more than 60% of the candidates on a list.

The first link above offers detail (in Spanish) about the debates and votes on specific provision, as well as which communes will be in which chamber district, and the district magnitudes for both chambers.

Chile’s election, 2013

Chileans went to the polls today in a general election (president and congress).

As of this time of posting, the count has just begun. I will update this space when there is more known. In the meantime, the profile of the three leading presidential candidates reads like a novel–and not only because the author is Ariel Dorfman.