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Latin America gets its own 538.com, and it beats the polls in Chile

Published in The Monkey Cage. Co-written with Stefan Bauchowitz.

The 2012 presidential election in the United States saw an increased popularity of poll aggregators such as Drew Linzer at Votamatic, Nate Silver at FiveThirtyEight and Sam Wang at Princeton Election Consortium. While their models significantly differ, they have one thing in common: their accuracy. With different methodologies Linzer’s, Silver’s and Wang’s forecasts were more accurate than those of any given pollster. They proved that aggregating polls could be more useful than using a single poll to predict the result of an election.

This prompted us, at TresQuintos, to develop a model of our own. We tested it on the 2013 presidential election in Chile, which took place Nov. 17. While we followed the methods of the poll aggregators named above, our model is mainly informed by statistics and political science literature (e.g. Andrew Gelman and Simon Jackman). Our forecast, too, was more accurate than the prediction of any given pollster. We also proved that aggregating polls could be more useful than using a single poll to predict the result of an election.

The following table shows the result of the election and the final forecast (of a longer series of forecasts) published by TresQuintos, four days before the election. It also shows a selection of pollsters that published their prediction of vote intention for each of the nine presidential hopefuls. All of these polls were fielded at the national level, some with face-to-face interviews and others via telephone. To compare them to the result of the election, we use their latest prediction and consider their valid preferences as the total sample.

2013 Chilean Election Forecasts and Results (Kenneth Bunker and  Stefan Bauchowitz/The Monkey Cage)

The following table shows that TresQuintos had the lowest total and average error. Some critics argue that forecasts made by poll aggregators should not be compared to predictions made by pollsters. We believe the contrary; poll aggregators and pollsters are essentially at odds. They compete against each other to get the numbers right. In countries where the media is highly politicized it is crucial to provide the public with as much unbiased information as possible. This is what Linzer, Silver and Wang did in the United States and what we did in Chile.

Total and Average Error of 2013 Chilean Election Forecasts (Kenneth Bunker and  Stefan Bauchowitz/The Monkey Cage)

Even though the idea of poll aggregation worked for us, we had to deal with a number of issues. We found the US and Chilean political contexts and polling scenes to be significantly different. In the US two-party system, voting intention for each candidate tended to be stable over time, and there were literally thousands of national and state-level polls to confirm trends. In Chile’s multi-party system, independent third-party candidates dominated fluctuations in public opinion, and there were only a handful of polls to keep track of variations.

The stable political system in the US, together with the high frequency of polls favored a model based on few assumptions. By contrast, Chile’s unstable political system, together with the low frequency of polls forced us to build a model with additional assumptions. Linzer’s, Silver’s and Wang’s models were more parsimonious than our model. However, in retrospect, we do not see this as an imperative. Instead, we simply understand it as a reflection of the advantages and limitations of the different political contexts and polling scenes.

A brief overview of how our model works will help clarify the similarities and differences with other poll aggregators.

At TresQuintos we use a two-stage process to aggregate polls. In the first stage we weigh polls according to their accuracy (pollster ranking), their non-forced error (sample size) and their age (distance to election). The two former steps allow us to calibrate poll predictions, and the latter allows us to estimate a time sensitive margin of error. In the second stage we (re)construct public opinion trends using Bayesian analysis: we assess the likelihood that a newly published poll is accurate given the information gathered from previous polls.

Part of the complexity of our model is given by theoretical factors. Complex models work well in complex systems. We don’t think a model as simple as those that had been successful in the US would have worked well in Chile. The other part of the complexity is given by environmental factors. When pollsters are substantially biased, it is extremely hard for simple aggregation models to get the numbers right. A theoretically complex model combines well with complex environmental settings.

Our forecast was extremely accurate in the point estimate, but fuzzy in the credibility interval. While we got the important numbers right, we had a large margin of error (see the following graph). This was mainly because of the divergent information being fed into the model. For some candidates, polling data were consistent across pollsters. For other candidates, polling data varied significantly. The accurate polls helped identify common point estimates, but the biased polls increased the credibility interval considerably.

2013 Chilean Election Forecast from tresquintos.com (Kenneth Bunker and  Stefan Bauchowitz/The Monkey Cage)

To our knowledge TresQuintos is the first successful poll aggregator in Latin America. The accurate forecast of the Chilean 2013 presidential election is the first look at a largely unexplored set of tools and body of literature in the region. The precedent set by Linzer, Silver and Wang is useful to frame poll aggregation, but we strongly believe that more complex models work better in developing democracies. The next step is to calibrate our model to forecast forthcoming elections in Brazil, Colombia and Uruguay.

Michelle Bachelet’s legislative majority

Published in Warscapes Magazine

On November 17, 2013 Chile will hold its sixth presidential election and seventh legislative election since the return of democracy in 1989.

The first four presidential elections were won by a coalition made up of socialists and Christian democrats (Nueva Mayoría). Initially founded as an opposition front to the authoritarian government, Nueva Mayoría evolved into a powerful center-left electoral machine. Under its umbrella, Patricio Aylwin, Eduardo Frei, Ricardo Lagos and Michelle Bachelet were each elected to govern for one term.

Things changed with the fifth presidential election—held in 2009—which marked the demise of the coalition. After twenty years of opposition, the right wing Alianza coalition took power by sweeping into the presidency. Two decades after the transition to democracy, Sebastián Piñera became the first right-winger to be democratically elected since Jorge Alessandri in 1958.

Piñera’s first couple years did not go smoothly. One issue had to do with the fact that the coalition that endorsed his candidacy had little to no experience in the executive branch. Most cabinet ministers appointed to the first cabinet were independents or businessmen from the private sector. This was bound to be a liability if political affairs took a downturn, as they eventually did.

In the midst of the massive student protests of 2011-2012 popular opinion held that Piñera’s   government simply could not solve pressing political issues. According to the well-known polling firm Adimark, the great majority of people did not approve of the president or of his cabinet. In fact, during the turmoil, Piñera plummeted to the lowest approval ratings since the transition to democracy.

Government response was swift. In early 2011, Piñera nominated four incumbent Alianza senators to key cabinet posts. This gave his administration an important boost in political dexterity. Among other things, the new cabinet ministers disembarked with the mission to maintain power past the end of the term. A mean to that objective inevitably involved toppling Bachelet’s potential reelection prospective. 

After leaving office in 2010, Bachelet had accepted a post at the United Nations as the Executive Director of UN Women. Based out of New York, she was only able to travel to Santiago a few times in her two-and-a-half year tenure at the UN. Nevertheless, Bachelet maintained the high approval ratings she enjoyed at the end of her presidential term even while she was gone. Her popularity approached an unprecedented 70 percent during her absence.

The government’s electoral strategy suffered its first major setback in the mid-term local elections of 2012. The symbolic win of the center-left coalition paved the way for a safe return of Bachelet from New York. A new and powerful coalition, in comparison to the old and fatigued coalition that lost the 2009 election, would be her vehicle back in to national politics.

In early 2013 Bachelet accepted to compete in the state-funded primaries scheduled for June that year. As an ex president, and the main alternative to Piñera’s unpopular administration, she hardly needed to campaign against her fellow coalition candidates. She won the primary election with an astonishing 73 percent of the vote. On the first day of July she officially accepted the nomination to be Nueva Mayoría’s presidential hopeful.

Beyond Bachelet’s remarkable return, the 2013 presidential election is unusual for a number of reasons. Most obviously, this year’s contest marks the first time since Chile’s transition to democracy that the incumbent Alianza will be forced to defend the presidency. The election is also unusual because it will be the first time that nine candidates will compete against each other. In previous elections the number of candidates fluctuated between three (in 1989) and six (in 1999). Interestingly, this election represents the first time that voting will be voluntary. In previous elections it was compulsory. Taken together, the number of candidates and the new voting scheme are bound to add uncertainty to the result.

Still, there is every indication that Bachelet will regain office in a landslide victory.  Every national poll shows Bachelet a majority of support, with a comfortable margin of 20 percent over her closest contender, Alianza’s Evelyn Matthei. What remains unclear is where whether Bachelet will win in the first or in the second round of voting.

One explanation for Bachelet’s commanding lead in the polls can be found not just in  her high approval ratings, but also in the public’s dissatisfaction with Piñera. The messy nomination process that Alianza undertook to nominate their candidate is also to blame. The center right coalition nominated three candidates in less than a year before finally settling with Matthei, who until recently served as Piñera’s Minister of Labor and Social Security.

In the first six months of 2013, the Alianza saw three former cabinet ministers rise as presidential hopefuls: Laurence Golborne, Andrés Allamand and Pablo Longueira. While Golborne was removed early on in the race, Allamand and Longueira battled it out in the June primaries. Shortly after Longueira beat Allamand, he stepped down claiming health issues. Longueira’s party reluctantly nominated Matthei.

Since it is likely that Bachelet win the presidential battle against Matthei, the focus of the election has shifted from the final results to Bachelet’s presidential agenda after she wins the presidency. Political analysts’ in the country have focused particularly on whether she will be able to accomplish three major reforms that have driven her campaign: tax reform, education reform and constitutional reform.

The sticking point for each of these reforms is found in the constitutional quorums required to pass them. With respect to tax reform, Chilean law requires only a simple majority of the chamber of deputies and the senate.  It gets quite a bit more complicated in the other two areas.  In order to reform the education system, 4/7 or 3/5 of the chamber of deputies must support the move, and constitutional reform is more difficult still, demanding quorums of 3/5 or 2/3 of the chamber of deputies and senate.

The latter two majorities have never been met. Those that designed the legislative electoral system purposely engineered a confusing and counterintuitive institution in which parties form coalitions, and coalitions tie in Congress. Despite the fact that though one coalition might win a substantial amount of votes, those votes do not translate directly into seats. Thus, the winning coalition’s ability to govern is blocked by an intentional subvention on behalf of the coalition that fails to win a majority. 

This intentional distortion makes it highly unlikely that any coalition will account for more than 4/7 of the senators and deputies during the next presidential term (2014-2018). This has particularly harsh implications for Bachelet’s agenda, given that keeping her promises depends directly on reaching the extraordinarily high constitutional quorums. The results could be dire, for Bachelet and her ruling coalition.

Bachelet would be well advised to heed the lessons learned by the current government. Piñera’s abysmal support derives from the high expectations of an electorate that was promised substantial benefits under a conservative government. Piñera’s failure to provide solutions to the problems of middle and lower class Chileans have led once hopeful voters to side with the opposition. This is a situation that is likely to repeat itself, if Bachelet’s coalition does not win the legislative election with a majority large enough to help the president-elect keep her promises.

Bachelet wins, but reforms on standby

Prepared for LSE IDEAS Blog

On November 17 2013, Chile held its sixth presidential election since the return of democracy in 1989. Since none of the nine presidential candidates received an absolute majority of the vote, the two top contenders will face off in a second round. On December 15, former president Michelle Bachelet will meet former cabinet minister Evelyn Matthei in a runoff election. Bachelet will represent the centre-left wing coalition’s attempt to regain control of government, and Matthei will represent the centre-right wing coalition’s bid to retain control of government.

Bachelet will likely win in the runoff. She obtained 47 percent in the first round, edging the absolute majority of the vote. Matthei is not expected to be a threat. She obtained 25 percent in the first round, matching the lowest support for a right-wing presidential hopeful in two decades. Although most of the polls overestimated the vote share for Bachelet in the first round, historical voting patterns point to a clean-cut victory in the second round. While hope persists in Matthei’s campaign base, doubling the percentage of votes seems like an impossible task (see here).

Because of Bachelet’s widespread favouritism, the larger part of the three month campaign gravitated around her presidential agenda. Mainstream media devoted the greater part of its political coverage to dissecting her government program. They specifically focused on her three most prominent promises and the possibility she could come through. They scrutinised her tax reform, educational reform and constitutional reform as well as questioned the likelihood that she would meet the legislative for each of them to pass through congress (see here).

During the three month campaign, media speculated on the level of success Bachelet’s future government could reach. The premise was that her success would hinge on her legislative majority. The key to a successful administration would come from the legislative election. To pass the tax reform she would need a simple majority of the 120-member chamber of deputies and the 38-member senate. To pass the educational reform she would need 4/7 of both chambers, and to undertake constitutional reform she would need 2/3 of both chambers.

The result of the legislative election quickly settled speculations. The Nueva Mayoría obtained 67 seats in the chamber of deputies and 21 seats in the senate. If Bachelet is elected in the second round, and her fellow coalition members elected to congress are disciplined, she will have enough votes to pass the tax reform but not enough votes to pass the educational reform or the constitutional reform (see here). In the light of these results, at best, Bachelet could only keep one of the three promises she pledged in her presidential program.

While the composition of the legislature will not allow Bachelet to unilaterally pass legislation in areas that require quorums higher than 4/7, she can still try and negotiate with other legislators (see here). Especially when it comes to the educational reform, where she is two votes shy of the 69 deputies and 22 senators required. The cohort that will be inaugurated concurrent to the next President will have four independent deputies and one independent senator. Bachelet best bet is to attempt to negotiate with them.

If Bachelet is elected to the presidency in the second round, and is successfully able to negotiate with the independents in congress, she will be able to undertake two of the three reforms she promised during her campaign. This is a likely scenario, given that two of the four independent deputies are student leaders of the 2010-2013 protests and are likely to fall in line with any reform to the educational system (see here). The independent senator may also decide to negotiate with Bachelet, if the conditions are favourable enough.

The worst possible outcome for Bachelet is if she cannot successfully partner with the independents, and has to resort to Alianza legislators. In this case, the odds she will be able to pass educational reform fall dramatically. Since legislative politics are substantially entrenched, it is unlikely right wing legislators will support left wing structural transformations of that nature. In this case, Bachelet would have to settle with the tax reform and suspend the educational reform – a gloomy scenario, given that most Chileans support both.

For now, Bachelet will be focused on securing a win in the second round – even though most of the game seems to have played out (see here). Because of the high prospective of Bachelet of winning in the runoff, and the result of the legislative election, the remainder of her campaign will be more focused on internal negotiations than traditional campaigning. The days to come will be about Bachelet and her negotiation with the independents. They will be about Bachelet and her attempt to secure at least two of her three campaign promises.

2013 Chile pre-election report: Bachelet will likely win, but watch the legislative results

Published in The Monkey Cage

The upcoming 2013 Chilean presidential election will be the sixth since the return of democracy in 1989. The first four elections (1989, 1993, 1999 and 2005) were won by the Concertación coalition, made up by center-left Christian Democrats and Socialists. The last election (2009) was won by the Alianza coalition, made up by two right-wing parties. At the time of the next election, the Concertación will have governed a combined 20 years while the incumbent Alianza will have governed four years. As in all previous elections, the Concertación and the Alianza will have the highest odds of electing the president.

The incumbent Alianza coalition, led by former senator and entrepreneur Sebastián Piñera, approaches the election with an extremely low chance of remaining in power. Piñera’s presidential approval ratings are the lowest any president has had since the transition to democracy. Figure 1 shows that Piñera’s popularity is significantly lower than any of the four preceding presidents’ ratings. The massive protests that lasted nearly two straight years (from 2011 to 2012) — demanding a new Constitution, among other things — have been signaled as the major factor behind his unpopularity.

Figure: Kenneth Bunker/The Monkey Cage

The main adversity that the Alianza faces, however, is the extremely low vote intention that it obtains in pre-election polls. Part of the reason is the dramatic process that the coalition undertook to nominate its candidate. In November 2012, former cabinet minister Laurence Golborne was nominated as the coalition hopeful. Yet, six months into his campaign, party members decided to discard his candidacy. In June 2013, his successor, Pablo Longueira, won the coalition’s primary election against Andrés Allamand, but resigned two weeks in. In July 2013, the third and final nomination went to Evelyn Matthei.

When compared to the Concertación candidate, ex-president Michelle Bachelet, Matthei is hardly competitive. In the most recent poll released to the media conducted by the prestigious think tank CEP, Bachelet topples Matthei by 44 percent to 12 percent. Bachelet’s lead is said to be a result of the high approval ratings that she obtained towards the end of her administration. But it is clearly a factor of the low approval ratings for Piñera and the dramatic nomination process his coalition went through to nominate its candidate. Figure 2 shows Bachelet’s margin of favoritism in all of the polls conducted since 2011.

Figure: Kenneth Bunker/The Monkey Cage

At this point, everything seems to indicate that Bachelet will be returned to the presidency. The large and consistent lead she has enjoyed in pre-election polls makes it reasonable to assume that if she does not win in the first round (in which an absolute majority of the vote is required), she will win in the runoff. It is precisely for that reason that the spotlight of the upcoming election will not be the result of the presidential election. In contrast to previous elections, the spotlight will be on the result of the concurrent legislative election, in which half of the senators (20) and all of the congressmen (120) are to be elected.

The legislative election is important for Bachelet’s presidential agenda. The highlight of her candidacy has been the promise to change the current Constitution (put in place by the military dictatorship, 1973-1990). To follow through, however, she must garner a legislative majority large enough to meet the extraordinarily high quorum required in Congress to pass that type of legislation. Bachelet needs at least two-thirds, three-fifths or four-sevenths (depending on the magnitude of the reform) of both the Senate and the Chamber of Deputies to conduct constitutional reform.

The problem is that while Bachelet’s legislative list may reach any of the given thresholds in the percentage of votes cast the in the election, the current electoral system does not translate voter preferences into an equal percentage of seats. The binomial electoral system (coined because of its two-seat across-the-board proportional representation arrangement for both Senate and lower chamber elections) only allows the most popular list in each district to take both seats available if it doubles the vote of the second most popular list. This has only happened five times in races for the Senate (of 132 possible) and 47 times in races for the lower chamber (of 360 possible).

For Bachelet to obtain a significant majority, her coalition needs to double the second most-voted list in four to seven senatorial districts and in nine to 20 lower chamber districts (depending on the quorum). Though the electoral force of the Alianza is at its lowest popularity levels since 1989 and Bachelet’s popularity is likely to generate a coattail effect and optimize the result of her legislative list, it is still an unlikely result. Even considering the new voluntary voting scheme (adopted in 2012), which works against unpopular incumbents, evidence stemming from previous elections indicates that the electoral system will work against overly large majorities.

The forthcoming presidential and legislative election will naturally frame the next government. But they will do more than just decide who will be the future president: The concurrent election will go a long way in forecasting the governability of the country during the next four-year term. If Bachelet is elected to the presidency with the legislative majority to undertake constitutional reform, voters will feel paid back insofar as changes are implemented. However, if Bachelet is elected without any of the aforementioned majorities, it is likely that she will face turmoil similar to the one Piñera has endured in the past three years.