Which of the following two factors, social cleavages or electoral institutions, better

Which of the following two factors, social cleavages or electoral institutions, better explain why Western European countries have different party systems? Critically evaluate the classical institutionalist and sociological traditions in light of the more recent literature, in order to account for party system variation in Western Europe. Please illustrate your argument with at least two country examples.
Please be sure that you clearly define the main concepts that you are seeking to explain, e.g. “political party,” “party system.”
What are the main types of explanations/the main causal factors that shape the party system? What are the strengths and weaknesses of each argument? How do they speak to each other?
Use these sources to answer the essay question.
The Context: Political Parties in Parliamentary and Semi-Presidential Systems
• Gallagher, Michael, Michael Laver and Peter Mair, (GLM). 2011. Representative Government in Modern Europe, Ch. 2 “The Executive,” pp. 23-46.
GLM, Ch. 3 “Parliaments,” pp. 47-83
Explanation 1: Social Cleavages
• GML, Ch. 9 “Cleavage Structure and Electoral Change,” pp. 263-306.
(The Chapter includes a summary of the Lipset & Rokkan’s 1967 Argument)
Explanation 3: Electoral Systems as Filters of Social Cleavages
• Cox, Gary. 1997. “Duverger’s Propositions.” Making Votes Count. Cambridge University Press, pp. 17-33.
Explanation 4: The Evolution of Social Cleavages and Electoral Institutions
• Caramani, Daniele. 2004. “Introduction.” The Nationalization of Politics. Cambridge University Press, pp. 1-12.
• Caramani, Ch. 6 “The Dynamic Perspective: State Formation and Democratization,” pp. 195- 250.
Explanation 5: Legislations /Legislative Behavior
· Koss, Michael. 2018 “How Legislative Democracy Creates Political Parties,” Comparative Politics, 51 (1), p.