Global Comparative Methods

Abstract

Comparative research is generally defined either at the level of systems (often national), or as a process by assessing politics over time (often yearly). Both descriptions are generally considered to differentiate the comparative approach from other approaches within social science such as rational choice. In line with this definition of comparative research, this chapter focuses on comparative studies in which the nation-state is the unit of analysis and countries are researched at one point in time or over time. Both time and space are important dimensions in most research designs. Depending on the units of variation and the causal relationship under review, inter-temporal and/or cross-sectional variation will define the type of cases that are needed to organize the comparative data. This chapter discusses the strengths and weaknesses of two types of comparative research designs whose logic is closely related to the dimensions of time and/ or space: synchronic cross-sectional comparisons and diachronic (pooled) cross-time comparisons. We make an important restriction by focusing on quantitative research, in particular time series analysis and the use of pooled cross-section time series data sets. Global comparative methods enable us to compare many countries by using abstract concepts that can travel in order to discover universal factors that account for the phenomenon to be explained. These types of analyses are often characterized by a tradeoff between the level of abstraction and the scope (or number) of countries so that they have per definition both strengths and weaknesses attached to them. The focus on quantitative analysis might give the impression that theory is not considered to be important for comparative research. But the contrary is true. Theory, considered as a set of plausible research answers to a research question, always precedes comparative research. Often it consists of a number of causal relations that are to be confirmed by means of empirical evidence, which refute or confirm the tenability of the proposed relations. Without theory or by using flawed theory, quantitative comparative research becomes meaningless and cannot lead to valid results and insights. 2