Political parties and institutional design: explaining constitutional choice in Latin America.

Since 1978, constitutional designers in Latin America have introduced institutional innovations, such as more-than-plurality rules of presidential elections, which aim at diffusing power by promoting multi-candidate competitions for the presidency. Paradoxically, however, constitution makers in this region have also adopted institutions that work in the opposite direction. New constitutions tend to increase the legislative powers of presidents, in particular, the power to promote legislative change. Why would politicians want to diffuse and concentrate power at the same time?

I argue that this choice is a by-product of the short-term interests of the makers of constitutions in an institutional setting where party systems are increasingly fragmented and parties are frequently factionalized. In this context, the representatives of electorally weak parties are likely to favour inclusive electoral rules, such as more-than-plurality rules of presidential election. They support these institutions to promote multi-candidate competitions for the presidency and party pluralism. In the same context, however, members of parties which control or expect to control the presidency are likely to favour presidents with strong powers to promote legislative change. They do so to invest the president with the capacity to provide public policy when his or her party lacks the support of a disciplined majority in congress. In the absence of a dominant party able to impose the selection of institutions, these contradictory demands become part of a bargaining package which attempts to satisfy the interests of the main actors.

The argument proceeds as follows. The first two sections provide an overview of the most significant changes in electoral rules and presidential legislative powers during the twentieth century in Latin America. The next section develops an analytic framework and proposes a number of hypotheses on constitutional choice. Then there is a discussion of the operationalization and coding of the main variables and testing of the hypotheses with a statistical analysis of the determinants of constitutional choice in forty-six cases of constitutional change in Latin America from 1900 to 2001. The article concludes with a discussion of the implications of the findings for the study of presidential democracies.

ELECTORAL RULES: FROM RESTRICTIVE TO INCLUSIVE

Until the first decade of the twentieth century, most countries in Latin America elected representatives by plurality rule in single-member or multi-member districts, sometimes in combination with a limited vote. A few countries had experiences with majority run-off systems. As in Western Europe at the time, however, negotiations between old and new parties soon led constitutional reformers in Latin America to shift from plurality or majority rule to proportional representation (PR). The trend started with Costa Rica in 1913, followed by Uruguay in 1917 and Chile in 1925. By 1978, fifteen out of eighteen countries had adopted variants of proportional formulas. But except for the early reformers, systematic implementation of the new proportional formulas was infrequent. Repeated cycles and long periods of authoritarian rule in most countries prevented proportionality from making a full impact on party systems and party competition until PR formulas were restored in the early 1980s. By 2000, all Latin American democracies were using variants of PR formulas for electing deputies in single or multiple tiers.

The next important electoral change in Latin America took place after 1978. The period of re-democratization that began in 1978 led to a gradual abandonment of simple plurality for electing presidents. Most countries shifted to alternative rules such as qualified plurality--plurality with a minimum threshold to win in the first run or majority run-off formulas. In addition, since the 1994 constitutional reform in Argentina, no country in Latin America has retained the typical nineteenth-century electoral system of electing a president indirectly by means of an Electoral College.

Eleven countries had experiences with plurality rule from 1900 to 1977. After 1978, however, the number of countries using plurality fell to eight during the 1980s and had dropped to five by 2000. During the same period, formulas other than simple plurality were on the rise. From 1900 to 1977, five countries had experiences with majority formulas (whether with a second round of elections or in Congress) and two countries with qualified plurality formulas in direct elections. After 1978, in contrast, ten countries adopted or maintained majority formulas and three utilized qualified plurality formulas. By 2000, only five countries in Latin America retained direct presidential elections by simple plurality: Honduras, Mexico, Panama, Paraguay and Venezuela. The rest had adopted or maintained more-than-plurality rules.

The rules for electing presidents have potentially significant effects on party competition. These effects depend on the percentage of votes that a candidate must attain to win the election. (2) In the absence of a threshold, plurality rule provides small parties with an incentive to endorse, at least in the long run, presidential candidates from parties or coalitions whose expected electoral support is large enough to challenge an incumbent. Over time, this tends to restrict the entry of small parties and encourage the building of two large blocs, one behind the front-runner and another behind the main challenger. (3) By contrast, majority rule sets a threshold that is often too high for any party to achieve. Thus it does not force small parties with different ideologies or popular candidates to form electoral coalitions in the first round. (4) By running alone, relatively small parties can expect to pass through to the second round and either win with the support of first-round losers or negotiate their support to one of the main candidates.

Qualified plurality works as an intermediate formula between plurality and majority rule. As long as the presidential candidate of one party is expected to reach the threshold established by the rule, the other parties have an incentive, just as in simple plurality, to coalesce before the election in support of a single opponent. But, if there are many candidates, none of whom is expected to reach the threshold, qualified plurality works precisely like majority rule, leading to multi-party competitions for the presidency.

These expected effects have been generally confirmed in empirical studies. It has been shown that the effective number of candidates competing in a presidential election is higher under majority run-off than under plurality. (5) There is also evidence that on average, presidential elections under qualified plurality systems lead to an effective number of candidates that is slightly higher than with plurality, but lower than with majority rule. (6) Related research has also shown that the formula for electing presidents, in combination with the temporal proximity of presidential and legislative elections, has an indirect impact on legislative fragmentation. In particular, temporally-proximate presidential elections tend to reduce the effective number of parties competing in legislative elections if and only if the effective number of presidential candidates is sufficiently low. (7)

Putting these findings together one can expect that compared to presidential elections by majority rule, presidential elections by plurality tend to reduce the effective number of candidates. In addition, if congressional elections are concurrent or close to the presidential election, plurality rule has, again compared to majority rule, an indirect reductive effect on the effective number of electoral parties. This suggests that in combination with the prior adoption of PR formulas for congressional elections, the recent shift from plurality to more-than-plurality rules for presidential elections in Latin America represents a shift from more to less restrictive rules on party competition.

The combined effect of the electoral rules for electing legislators and presidents has supported and reinforced multi-partism in the region. As of 2000, for instance, only six out of eighteen countries in Latin America had an effective number of parties in the single or lower chamber of congress less than 2.5. In most cases, the president's party has had a minority status in congress. To overcome this situation, presidents have managed to form government coalitions or rely on legislative coalitions. Often, however, presidents have also been able to compensate the minority status of their parties with constitutional powers that give them influence over legislative bargaining. In fact, just as the proliferation of parties has made presidents more dependent on congress for implementing a legislative agenda, several constitutional changes have increased their formal powers to negotiate policy with legislators. I turn to the analysis of these transformations in the next section.

POLICY-MAKING RULES: FROM REACTIVE TO PROACTIVE PRESIDENTS

At the beginning of the twentieth century, most presidential regimes in Latin America maintained the US model of separation of powers that was adopted after the wars of independence. (8) The US Constitution invested the president with the power to preserve the status quo by means of a package veto, but it deprived the executive of any specific agenda-setting power, that is, the power to constrain the set of policy alternatives from which the assembly may choose, the timetable according to which these choices must be made, or both. This institutional arrangement was, however, gradually transformed.

Along with the traditional package veto, the 1949 Argentine Constitution and the 1967 Uruguayan Constitution invested presidents with the explicit authority to veto portions of a bill and promulgate the rest if congress did not achieve the majorities necessary to override the partial observation. In terms of agenda powers, the 1917 Uruguayan Constitution introduced the concept of reserved areas of exclusive initiative of the executive on important financial and economic matters. Some constitutions, like the 1925 Chilean Constitution or the 1946 Ecuadorian Constitution, increased the influence of executives on the drafting of budget bills by making the presidential proposal the reversionary outcome if congress did not decide within a time limit. Presidents also received the power to force a congressional vote on a government bill within a constitutionally defined time limit, as was the case of the 1925 Chilean Constitution, the constitutional reform of 1945 in Colombia, and the 1967 Uruguayan Constitution. The 1937 Brazilian Constitution invested the president with the explicit power to enact decrees of legislative content in cases of urgency. Later, this precedent was followed by the 1946 Ecuadorian Constitution and the constitutional reform of 1968 in Colombia.

A few countries revising their constitutions after 1978, such as Nicaragua and Panama, have reduced the presidential powers inherited from an authoritarian constitution. Other countries moderated presidential powers created by authoritarian constitutions while retaining important prerogatives for the executive, as was the case in Brazil and Paraguay. In most cases, however, constitutional changes since 1978 led to a net increase in the legislative powers of the president, particularly in the area of agenda powers. (9)

The 1979 Constitution of Peru and the 1998 Constitution of Ecuador reinforced the agenda-setting powers of presidents over the budget by placing limits on the ability of legislators to increase the total level of spending authorized by the executive. The 1979 Constitutions of Ecuador and Peru, the 1988 Constitution of Brazil and the 1992 Constitution of Paraguay gave presidents the capacity to invoke urgency bills that must be voted on within a time limit. In some cases (Ecuador, Paraguay and Uruguay), the constitution even establishes that the bill proposed by the executive becomes law in the absence of congressional approval. The clearest example of the strengthening of the legislative powers of presidents in recent years is, of course, the growing number of constitutions that invest the executive with the power to enact decrees of legislative …