My work on multi-method research deals with the integration of case studies and process tracing with regression analysis and Qualitative Comparative Analysis (QCA). Based on my paper in Comparative Political Studies, I explore several issues concerning the combination of case studies and regressions. Work in various stages of progress concerns the generalization of process-tracing insights in multimethod research (with David Kühn); formalized case selection in QCA and the linkage between QCA and mechanisms (with Carsten Q. Schneider); formalized case selection based on regression analysis.
Rohlfing, Ingo and Carsten Q. Schneider (2016): A unifying framework for causal inference in set-theoretic multi-method research. Sociological Methods & Research (advance access)
Schneider, Carsten Q. and Ingo Rohlfing (2016): Case studies nested in fuzzy-set QCA on sufficiency: formalizing case selection and causal inference. Sociological Methods & Research 45 (3): 526-568
Rohlfing, Ingo and Peter Starke (2013): Building on solid ground: Robust case selection in multi-method research. Swiss Political Science Review 19 (1): 492-512
Schneider, Carsten Q. and Ingo Rohlfing (2013): Combining QCA and process tracing in set-theoretic multi-method research. Sociological Methods & Research. 42 (4): 559-597 [supplementary material]
Rohlfing, Ingo, and Carsten Q. Schneider (2013): Formalized case selection for process tracing after QCA: the case of necessity. Political Research Quarterly 66 (1): 220-235 (unfortunately, PRQ only offers a URL for the symposium of which the article is a part of) [supplementary material]
(2008): What you see and what you get: Pitfalls and principles of nested analysis in comparative research. Comparative Political Studies 41 (11): 1492-1514