64% Majority Rule in Ducal Venice: Voting for the Doge
By Jay S. Coggins and C. Federico Perali
Public Choice, Vol. 97, No. 4 (1998)
Abstract: A recent result of Caplin and Nalebuff (1988) demonstrates that, under certain conditions on individual preferences and their distribution across society, super-majority rule performs well as a social decision rule. If the required super-majority is chosen appropriately, the rule yields a unique winner and voting cycles cannot occur. The voting procedure for electing a Doge in medieval Venice, developed in 1268, employed a super-majority requirement agreeing with the Caplin and Nalebuff formula. We present a brief history of the Venetian political institutions, show how the rule was employed, and argue that it contributed to the remarkable centuries-long political stability of Venice.
Introduction: During its golden age, Venice was among the world’s premier cities, boasting a population of some 160,000 in the year 1300. Her citizens were innovators in commerce, in armaments, in architecture and the arts, in the creation of ocean-going vessels and in their navigation. As merchants and artisans, manufacturers and craftsmen, marauders and statesmen, they had few peers. From the sixth century to the end of the eighteenth, Venice was a separate state, entirely independent after 810. At a time when most political communities across the globe experienced the rise of monarchies, Venice retained her republican city-state institutions and continued as a potent diplomatic and commercial force from England to Russia.
How was Venice able to preserve herself for over 12 centuries, her status as a financial center and, especially in the last three centuries, as an artistic center intact and for lengthy periods unchallenged? The secret appears to lie to a considerable degree in the political institutions by which Venice was governed. From about 1000 onward, there appeared a steady flow of innovations in the political processes by which public decisions were reached and executed. The element of chance, as we shall see, played a central role in political life. Even more important, though, was the menu of nomination and voting schemes used by the leading families to elect officers to posts all the way from minor administrative councils to the pre-eminant political office of the city, the dogeship (or dukeship) of Venice.