a1 Harvard University
Why was there an abrupt increase in economic openness in Europe in the 1860s? This increase may have been the result of a contagion process, in which the Cobden-Chevalier treaty between Britain and France threatened to displace third-party exports to France with British exports. As a result, most European states signed similar treaties with France, which had further ripple effects.
This article outlines a formal model of this process, based on the assumption that an agreement between two states increases the desirability of similar treaties to third parties. Propositions regarding the rate and pattern of spread of treaties are derived from this model. This article then discusses the insights these propositions may offer into the rise and fall of the most-favorednation network of treaties between 1860 and 1929.
At a theoretical level the model aims to link the microlevel processes underlying state preferences to system-level phenomena. At a substantive level this analysis offers insight into the current explosion of regionalism.
David Lazer is Assistant Professor of Public Policy at the Kennedy School of Government at Harvard University. He has written on the dynamics of network formation in a variety of political contexts and is currently completing a book manuscript on the spread of preferential trade agreements.
* I acknowledge with gratitude helpful comments from Robert Axelrod, Lisa Bernt, Darcie Dennigan, George Downs, Ted Hopf, Douglas Irwin, Estelle James, Peter Marsh, Walter Mattli, Timothy McKeown, Andrew Moravcsik, and Robert Pahre, as well as participants in colloquia at Princeton and UCLA. However, I retain exclusive rights to any errors contained herein.