The Comparative Method

Plenty of political scientists will say that one of the ways – or perhaps the way they study politics is by using the comparative method. You may hear some distinguish their work by saying that that they are ‘comparativists’, or that they work in the subfield of ‘comparative politics’. What do they mean? There is no such thing as a research method that is not comparative. As Swanson nicely puts it ‘thinking without comparison is unthinkable’ (cited in Ragin, 1987: 1). Every thought or action we come across is understood with reference to previously acquired information, thoughts and experiences. Why then do political scientists talk about a distinctive comparative method? This chapter answers that question by first explaining the historical development of comparison in the study of politics. I then present ‘Mill’s methods’ and update them by drawing a lineage to current developments in case-based/set-theoretic methods, providing examples along the way. The chapter focuses on important debates about how cases are chosen for comparison and discusses critiques of comparativists’ research strategies. I discuss how recent evolutions in methods and approaches in the discipline pose difficulties for proponents of a distinctly valuable comparative method. I argue, nevertheless, that the strategic expertise of a good comparativist is witnessed in their sensitivity to the implications of trade-offs among different sampling strategies for explaining and predicting politics.