Presidentialism, Parliamentarism, and Democracy by José Antonio Cheibub, Professor of Comparative Politics, Texas A&M University; Cambridge University Press, New York; 2007.
[By Bhanu Dhamija]Follow @bhanudhamija
Presidentialism’s defining characteristic is the separation of executive and legislative powers, while Parliamentarism is based on their fusion. Since the 1990s, the conventional wisdom in the political science community has been that the separation of powers makes the presidential system more prone to breakdown, and that this makes democracies fall to autocratic rule. But Professor Cheibub’s study of every democracy that existed between 1946 and 2002 showed that both contentions are false.
The belief that Presidentialism is fragile and prone to authoritarianism was based mainly on the works of political scientist Juan Linz. In a series of articles and books in the 1990s, Linz tried to explain the breakdown of many presidential democracies by positing that presidential constitutions have an inherent flaw because of their separation of powers. Since both the executive and legislative authorities are elected directly by the people, they have little interest in forming coalitions, accommodating multiple parties, and cooperating in legislative programs. “Conflict is always latent and sometimes likely to erupt dramatically … there’s no democratic principle to resolve it,” Linz said.
The United States, the world’s longest lasting democracy, baffled Linz with its Presidential system. He conceded “the uniqueness of American political institutions and practices that have limited the impact of such conflicts.” [p.7] But for decades his view that the Presidential system contributes to democratic breakdown held. Most challengers to his view analyzed only a handful of democracies and Linz was able to dismiss their selectiveness as “dubious.” [p.74]
Cheibub studied all 135 democracies that existed during this 56-year period and found no evidence that Presidentialism is prone to democratic breakdown. He looked for empirical evidence of every ailment that Linz believed was caused by the separation of powers: undisciplined political parties; no incentives for coalition formation; lack of minority governments, and legislative deadlocks. Cheibub concluded, “Little in the chain of reasoning that leads from separation of powers to the instability of presidential regimes can be supported either theoretically or empirically.” [p.136]
Since there’s nothing inherently wrong with the Presidential system, Cheibub went further and explored why the Presidential democracies had shorter lifespans than the Parliamentary ones (24 years vs. 58, during the half-century studied). He found that the usual explanations—that parliamentarism is more frequent in wealthier countries, or in smaller nations, or in the stable countries of Europe—do not fully account for the different survival rates. What he discovered instead was that “Presidential democracies have existed in countries where the environment is inhospitable for any kind of democratic regime.” [p.136]
Cheibub found that Presidential democracies followed military dictatorships more frequently than civilian ones, and such democracies had shorter lifespans. He explained: “Two stories… can be constructed to account for these patterns. In one the military-presidential nexus is causal; in the other it is purely coincidental, the product of historical accident. I argue that the first story, while plausible, is not empirically accurate, whereas the second is compatible with empirical evidence.” [p.145]
He thus concluded, “The problem of presidential democracies is not that they are ‘institutionally flawed’. Rather, the problem is that they tend to exist in societies where democracies of any type are likely to be unstable.” [p.160]
The book is a definitive rejection of received wisdom that the Presidential system is fragile or contributes to authoritarian rule. Since its publication, the debate has shifted from finding fault with Presidentialism’s separation of powers to its “executive personalism,” the assigning of all executive powers to a single individual.
Such debates aside, the academic community still has to contend with the fact that presidentialism has created in the United States history’s longest lasting democracy, which has never fallen to autocratic rule. The country has confidently elected former military generals as President, 12 times in fact, without any fears of becoming a dictatorship.
The problem with any comparative study is that all the Presidential democracies of the world except the United States are Presidential in name only. The U.S. system is so distinctive that a group of political scientists led by Arend Lijphart found that no other country has the same mix of institutions, power distribution, and checks and balances.
It’s ironic that for years many political scientists argued that the separation of powers is bad, and their fusion strengthens democracy. Cheibub’s book makes a huge contribution by correcting this mistaken belief.
 The Failure of Presidential Democracy, Juan J. Linz and Arturo Valenzuela, 1994
 Beyond Presidentialism and Parliamentarism by Steffen Ganghof, Oxford University Press, 2021