Disclaimer. Don't rely on these old notes in lieu of reading the literature, but they can jog your memory. As a grad student long ago, my peers and I collaborated to write and exchange summaries of political science research. I posted them to a wiki-style website. "Wikisum" is now dead but archived here. I cannot vouch for these notes' accuracy, nor can I even say who wrote them. If you have more recent summaries to add to this collection, send them my way I guess. Sorry for the ads; they cover the costs of keeping this online.
Martin and Stevenson. 2001. Government formation in parliamentary democracies. Journal of Political Science 45 (January): 33-50.
An empirical evaluation of several traditional theories about cabinet formation. Assesses the "impact of recent new-institutionalist theories on our ability to explain and predict government formation." A review of prominent theories. See notes.
Main point: Most of these hypotheses are partly right. All the various theories of cabinet formation are partly significant. It's like each theorist is blindfolded and touching part of an elephant: they haven't yet figured out what the whole animal looks like. Martin and Stevenson encourage an integration of the various theories to form a more inclusive theory of the whole elephant.
Research on similar subjects