Democratization Index in the Polity Dataset
Tatu Vanhanen (ed.), Strategies of Democratization
(Washington, D.C.: Crane Russak, 1992), pp. 22-23.

Operational indicators of democratization have been formulated and used in numerous comparative studies, but these indicators differ considerably from each other. I have referred to a number of them in my earlier studies because my own indicators are to some degree related to them (see Vanhanen 1984, 1990). I wanted to construct a measure of democratization based on quantitative indicators, a measure that can be applied to all contemporary countries and that takes into account the most important dimensions of democracy. How then to construct such a measure of democratization?

Two theoretical dimensions of democratization--public contestation and the right to participate--examined by Robert A. Dahl (1971) seem to correspond to those characteristics of political systems that best differentiate more democratic systems from less democratic ones. I have called these dimensions "competition" and "participation." The existence of legal competition means that individuals and groups are free to organize themselves and to oppose the government. It also implies the existence of some degree of equality in the sense that different groups are equally free to compete for power. The degree of participation in crucial decision-making processesÐeither through elections or by some other meansÐis indicative of the relative number of people taking part in politics in general. The higher the degrees of competition and participation, the higher the level of democratization in a particular political system.

I have used the electoral success of the smaller parties, i.e., the proportion of the votes won by those parties in parliamentary and/or presidential elections, to indicate the degree of competition in a given political system. This figure is calculated by subtracting the percentage of the votes won by the largest party from 100 percent. If both parliamentary and presidential elections are taken into account, the arithmetic mean of the two percentages is used to represent the smaller parties' share of the vote cast.

The percentage of the population that actually voted in these elections is used as a measure of the degree of electoral participation. It should be noted that this percentage is calculated from the total population, not from the adult population or from the enfranchised population. Because these two variables are assumed to represent different dimensions of democratization, it is plausible to assume that a combination of the two would be a more realistic indicator of democratization than either of them alone.

The variables could be combined in many ways, depending on how we weight the importance of competition and participation. It seems to me impossible to determine which of them is more important or how much more important; therefore, I have chosen to weight them equally in the construction of an index of democratization (ID). This is formed by multiplying the variables and dividing the outcome by 100. This means that a low value of either of the two variables is enough to indicate a low level of democratization. I believe that a high value of participation cannot compensate for a lack of competition, and vice versa. The ID is my principal indicator of democratization.

return to description of polity variables

Dahl, R.A. 1971. Polyarchy: Participation and Opposition. New Haven and London, Yale University Press.

Vanhanen, T. 1984. The Emergence of Democracy: A Comparative Study of 119 states, 1850-1979. Helsinki: The Finnish Society of Sciences and Letters.

Vanhanen, T. 1990. The Process of Democratization: A Comparative Study of 147 states, 1980-1988. New York: Crane Russak.

See also: Kenneth Janda, review of Vanhanen, T. 1990. The Process of Democratization: A Comparative Study of 147 states, 1980-1988, in The Journal of Politics, 54 (August, 1992), 928-930.