Party Aggregation and the Number of Parties in India and the United States

Abstract

¥" T "Te rely on data from India and the United States to show that political and economic centralization 1 / 1 / can influence the number of national parties in single-member simple-plurality electoral systems. V V Historically, in both countries the number of parties in local electoral districts has been near two, but the number of national parties has fluctuated. Periods of a small number of national parties in both countries correspond to periods of centralization. We argue that, as national governments centralize power and make policies that affect local areas, candidates have greater incentives to associate with national organizations, and voters have greater incentives to abandon locally competitive but nationally noncompetitive parties. P rominent explanations for differences in the number of political parties across countries, most notably Duverger's Law and the literature related to it, have focused on the role of electoral systems. Differences in district magnitude, electoral formulas, the number of run-offs, and presidentialism have each been hypothesized as determining the number of parties (Cox ). Ethnic heterogeneity has also been associated with multiple party systems.' In accounting for changes in the number of national parties over time within individual countries, however, explanations based solely on electoral systems or population diversity are strained. These features rarely change much within countries, and certainly not as often as party systems undergo change in some countries, such as Italy, India, Mexico, or even, as we shall show, the United States. We examine party system change in India and the United States. Both countries are federal (with relatively strong state governments), and both have singlemember, simple-plurality electoral systems. Yet, in both countries the number of parties has varied over

Effective number of parties for incomplete data

“…Subtracting R from P, as if the 'Other' votes did not exist, yields 3.45. This figure seems to agree with Chhibber and Kollman (1996). As shown earlier, it is below the logically possible range for given R.…”

“…At the 1996 annual meeting of the American Political Science Association, for example, N was used in assessing evolution of party systems in Poland (Jasiewicz, 1996), Russia (Moser, 1996) and ThirdWave democracies (Goodson, 1996), as well as the effect of fiscal centralization on party aggregation (Chhibber and Kollman, 1996), and impact of electoral systems on budget deficits (Hallerberg and yon Hagen, 1996). 2.…”

Ideological externalities, social pressures, and political parties

“…On the other hand, a voter will be more concerned about influencing the views of MCs from other districts when the federal government centralizes power than when local governments exert much control. Chhibber and Kollman (1998), examining India and the United States, indeed find that periods with few national parties correspond to periods of centralization.…”

Duverger's Law and the Study of Electoral Systems

“…Accordingly, studies of Duvergerian effects at both the cross-national and national level tend to control for the influence of social factors. For instance, the Indian 'exception' to Duverger's Law (as a simple-majority single-member district system) is explained by the existence of deep social cleavages generating nearly four effective parties in equilibrium rather than two (Chibber and Kollman, 1998). Social divisions are often reinforced by federal institutions, permitting multipartism or even different party systems to exist at subnational levelsan explanation applied to Duvergerian exceptionalism in both India and Canada (Gaines, 1999).…”