Oslo Summer School in Comparative Social Science Studies 2011

Qualitative Comparative Analysis (QCA) and Fuzzy Sets

Lecturer: Dr Claudius Wagemann
Instituto italiano di scienze Umane (SUM)
Florence, Italy

Main disciplines: Sociology, Political Science, Research Methods
Dates: 1 - 5 August 2011
Course Credits: 10 pts (ECTS)
Limitation: 20 participants

 

Objectives
The method of Qualitative Comparative Analysis (QCA) is an important addition to standard statistical techniques and case-based comparisons, and contributes new perspectives to the scientific analysis of social phenomena. Being based on set-theoretical thinking, QCA helps researchers to analyze patterns of necessity and sufficiency in causally complex settings. Complexity in this sense refers to equifinal, conjunctural and asymmetric causal relations. Without losing its case-oriented character, QCA serves thus as a systematic and formalized technique of comparison. As a positive side-effect, it also enables the researcher to deal with mid-sized case numbers, allowing for research designs in which the analysis of between 10 and 100 cases is foreseen. Possible applications of QCA can be found in many areas of political science and sociology, but also in psychology, anthropology and even linguistics.

This course is a complete introduction to QCA, understood both as a research design and as an analytical technique. After an epistemological overview of where to place QCA within the canon of social science methodology, the variant of crisp-set QCA (csQCA) is introduced. Although being of more limited use in its application (since all ‘variables’ have to be dichotomous), the technical procedures for csQCA correspond to every-day thinking. In a subsequent step, the various rules, algorithms, and mathematical operations are then extended to the fuzzy set version (fsQCA) where non-dichotomous data can be analyzed and which has become the standard QCA technique. Towards the end of the course, we will come back to the initial question, of which use QCA can be within the social science methodology and develop criteria for a ‘good quality’ QCA.

No prior technical or mathematical knowledge is needed. Familiarity with methodological questions and comparative methods in general will be helpful. The course will cover most topics of the available methodological literature on QCA and can be regarded as a complete introduction to the state of the art. The main emphasis of the course is on analytical procedures and their application in empirical social science research. Epistemological topics are mentioned and discussed in the beginning and at the end of the course. Two sessions are reserved for computer applications of QCA and for an introduction to the fsQCA computer program. However, this is not a training course on the use of various software packages, but qualifies the participants for the independent use of them.

 

Requirement
Participants should bring their own laptops and make sure to install the program on it. This can be found at http://www.u.arizona.edu/~cragin/fsQCA/software.shtml
- we only need the fsQCA software, not the DOS version (just click on the download button).

 

Essential readings:

  • Goertz, Gary and James Mahoney (2006). “A Tale of Two Cultures: Contrasting Quantitative and Qualitative Research”. Political Analysis, 14 (3) 227-249.
  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 1-33.
  • Ragin, Charles C. (2009). “Qualitative Comparative Analysis Using Fuzzy Sets (fsQCA)”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 87-121.
  • Rihoux, Benoît and Gisèle De Meur (2009). “Crisp-Set Qualitative Comparative Analysis (csQCA)”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 33-68.
  • Wagemann, Claudius and Carsten Q. Schneider (2010). “Qualitative Comparative Analysis (QCA) and Fuzzy Sets: the Agenda for a Research Approach and a Data Analysis Technique”. Comparative Sociology, 9 (3)376-396.

 

LECTURE OUTLINE

Lecture 1: QCA in Context I: Why a “Third Way” is Needed

In this lecture, we will take up the discussion about ‘qualitative’ and ‘quantitative’ methodology (or, as preferred by some scholars: case-oriented vs. variable-oriented methods). We will work out the main differences between the two camps and see where QCA can be located. We will especially clarify, if it makes sense to speak about a “third way” and, if so, if and why QCA can count as an example for it.

Readings:

  • Goertz, Gary and James Mahoney (2006). “A Tale of Two Cultures: Contrasting Quantitative and Qualitative Research”. Political Analysis, 14 (3) 227-249.
  • Della Porta, Donatella (2008). “Comparative Analysis: Case-Oriented Versus Variable-Oriented Research”, in Donatella della Porta and Michael Keating (eds.), Approaches and Methodologies in the Social Sciences. Cambridge: Cambridge University Press, pp. 198-222.
  • Ragin, Charles C. (2004). “Turning the Tables: How Case-Oriented Research Challenges Variable-Oriented Research”, in Henry E. Brady and David Collier (eds.), Rethinking Social Inquiry. Lanham et al.: Rowman & Littlefield, pp. 123-138.
  • Hall, Peter (2003). “Aligning Ontology and Methodology in Comparative Research”, in James Mahoney and Dietrich Rueschemeyer (eds.), Comparative Historical Analysis in the Social Sciences. Cambridge: Cambridge University Press, pp. 373-404.
     

 

Lecture 2: QCA in Context II: Principles of Comparative Methods

The first publication on QCA techniques was entitled ‘The Comparative Method’ (Ragin 1987), underlining that QCA must not be seen isolated from other social science methods, but is part of a larger literature on comparative methods. In this lecture, we will see how this methodological field is composed, what the shortcomings of many comparative methods are, and why QCA is part of and even fills a gap in comparative methodology.

Readings: 

  • Mahoney, James (2003). “Strategies of Causal Assessment in Comparative Historical Analysis”, in James Mahoney and Dietrich Rueschemeyer (eds.), Comparative Historical Analysis in the Social Sciences. Cambridge: Cambridge University Press, pp. 337-372.
  • Lieberson, Stanley (1991). “Small N’s and Big Conclusions: An Examination of the Reasoning in Comparative Studies Based on a Small Number of Cases”. Social Forces 70 (2): 307-320.
  • Wagemann, Claudius and Carsten Q. Schneider (2010). “Qualitative Comparative Analysis (QCA) and Fuzzy Sets: the Agenda for a Research Approach and a Data Analysis Technique”. Comparative Sociology, 9 (3) 376-396.
     

 

Lecture 3: Boolean Algebra, Set Theory and the Analysis of Truth Tables

Although not being a statistical (“quantitative”) method, QCA nevertheless has a mathematical foundation, most importantly set theory, formal logic and Boolean algebra. This lecture provides the necessary knowledge about the basic operations of these mathematical sub-disciplines. This will lead us to a first analysis of truth tables, in order to examine the presence of necessary and sufficient conditions, also introducing two basic formalized QCA techniques.

Readings:

  • Klir, George J., Ute St. Clair and Bo Yuan (1997). Fuzzy Set Theory. Foundations and Applications. Upper Saddle River (NJ): Prentice Hall PTR, pp. 47-72.
  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 1-28.
  • Ragin, Charles C. (1987). The Comparative Method. Moving Beyond Qualitative and Quantitative Strategies. Berkeley et al.: University of California Press, pp. 85-102.

 

Lecture 4: Limited Diversity and Easy Counterfactuals

Many QCA analyses suffer from the problem that not all theoretically possible information is empirically available. This is also referred to as the problem of ‘limited diversity’. QCA offers various ways of ‘troubleshooting’ in such a situation, most of them based on sub-set-super-set relations (and not, as often believed, on a parsimony-complexity continuum). Additionally, rather recently developed theory-guided thought experiments and easy counterfactuals which allow for so-called ‘intermediate solutions’ will be introduced. But also some other proposals will be made about how to effectively deal with the problem of ‘limited diversity’.

Readings: 

  • Ragin, Charles C. (1987). The Comparative Method. Moving Beyond Qualitative and Quantitative Strategies. Berkeley et al.: University of California Press, pp. 103-124.
  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 147-175.
  • Emmenegger, Patrick (2010). How Good are Your Counterfactuals? Assessing Quantitative Marco-Comparative Welfare State Research with Qualitative
    Criteria
    , Compasss Working Paper 2010-59, Online: http://www.compasss.org/files/WPfiles/Emmenegger2010a.pdf

 

Lecture 5: Evaluation Parameters and Consequences from Incomplete Truth Tables

Although often claimed, it is simply wrong that QCA is an exclusively deterministic method. Evaluation parameters have been developed (namely the consistency and coverage measures) which allow for a deviation from perfectly deterministic results. In this session, these measures are presented and compared to similar parameters in standard statistical research. In this context, we will also discuss which consequences incomplete truth tables can have for QCA analyses.

Readings: 

  • Ragin, Charles C. (2006). “Set Relations in Social Research: Evaluating Their Consistency and Coverage.” Political Analysis 14 (3): 291-310.
  • Goertz, Gary (2006). “Assessing the Trivialness, Relevance, and Relative Importance of Necessary or Sufficient Conditions in Social Science.” Studies in Comparative International Development 41 (2): 88-109.
  • Schneider, Carsten Q. and Bernard Grofman (2009). "An Introduction to Crisp-Set QCA, with a Comparison to Binary Logistic Regression". Political Research Quarterly, 62, 4: 662-672.

 

Lecture 6: Using the fsQCA Computer Software

This lecture will be dedicated to the use of the most widely diffused QCA software. The theoretically acquired knowledge on csQCA will be applied to fake datasets as well as to a re-analysis of previously published work. The session also serves as a wrap-up of the csQCA part of the course and prepares for the subsequent use of fuzzy sets.

Readings:

  • Ragin, Charles C. (2008). User’s Guide to Fuzzy-Set / Qualitative Comparative Analysis. Typescript (http://www.u.arizona.edu/~cragin/fsQCA/download/fsQCAManual.pdf), pp. 1-22, 33-70
  • Rihoux, Benoît and Gisèle De Meur (2009). “Crisp-Set Qualitative Comparative Analysis (csQCA)”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 33-68.

 

Lecture 7: Fuzzy-Sets and Fuzzy-Algebra

Whereas csQCA can be regarded as a systematic application of rules and procedures which have already been known in the comparative social sciences for long time, fuzzy sets present a real novelty. Their use is closely linked to the issue of concept formation in comparative social science. This lecture introduces to the definition of fuzzy values and also presents the most important operations of fuzzy algebra, fsQCA’s equivalent to Boolean algebra.

Readings: 

  • Goertz, Gary (2005). Social Science Concepts. A User’s Guide. Princeton: Princeton University Press, pp. 27-68.
  • Klir, George J., Ute St. Clair and Bo Yuan (1997). Fuzzy Set Theory. Foundations and Applications. Upper Saddle River (NJ): Prentice Hall PTR, pp. 1-9, 90-95.
  • Ragin, Charles C. (2000). Fuzzy-Set Social Science. Chicago and London: The University of Chicago Press, pp. 149-180.
  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 29-37, 71-105.

 

Lecture 8: Property Spaces, Ideal Types and the Analysis of Sufficiency and Necessity

Since csQCA is a special version of fsQCA, the procedures in csQCA are usually simpler than in fsQCA. In this session, we will apply the technical knowledge from csQCA to fuzzy sets and see how – using the concepts of property spaces and ideal types – fuzzy set analyses are converted into the analysis of a truth table. Consistency measure will help us to identify valid sufficient and necessary conditions.

Readings: 

  • Ragin, Charles C. (2000). Fuzzy-Set Social Science. Chicago and London: The University of Chicago Press, pp. 181-202.
  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 38-68.

 

Lecture 9: The fsQCA Algorithm

In this session, we will bring together all the knowledge acquired in the other sessions and run an fsQCA from the beginning to the end. All steps of the analytical process will be explicated and potential pitfalls will be shown. A part of the lecture will be devoted to two-step approaches which differentiate various forms of causality and which render fsQCA more applicable to real-world research situations.

Readings:

  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 124-144.
  • Ragin, Charles C. (2009). “Qualitative Comparative Analysis Using Fuzzy Sets (fsQCA)”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 87-121.
  • Schneider, Carsten Q. und Claudius Wagemann (2006). “Reducing Complexity in Qualitative Comparative Analysis (QCA): Remote and Proximate Factors and the Consolidation of Democracy”. European Journal of Political Research, 45, 5: 751-786.

 

Lecture 10: Using the fsQCA computer software

As lecture 6, this lecture will also be dedicated to the use of the computer software, this time executing a full fsQCA. This also includes a discussion of the standards of good practice which a ‘good quality’ QCA should fulfill. In this session, we will also evaluate QCA as such and discuss, in how far it can be really considered a useful addition to the methodological repertoire of the social sciences.

Readings: 

  • Ragin, Charles C. (2008). User’s Guide to Fuzzy-Set / Qualitative Comparative Analysis. Typescript (http://www.u.arizona.edu/~cragin/fsQCA/download/fsQCAManual.pdf), pp. 23-32, 71-87
  • Schneider, Carsten Q. and Claudius Wagemann (2010). “Standards of Good Practice in Qualitative Comparative Analysis (QCA) and Fuzzy Sets”. Comparative Sociology, 9 (3) 397-418.
  • Rihoux, Benoît, Charles C. Ragin, Sakura Yamasaki and Damien Bol (2009). “Conclusions – The Way(s) Ahead”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 167-177.
  • Ragin, Charles C. (1987). The Comparative Method. Moving Beyond Qualitative and Quantitative Strategies. Berkeley et al.: University of California Press, pp. 164-171.

 

Complete reading list:

  • Della Porta, Donatella (2008). “Comparative Analysis: Case-Oriented Versus Variable-Oriented Research”, in Donatella della Porta and Michael Keating (eds.), Approaches and Methodologies in the Social Sciences. Cambridge: Cambridge University Press, pp. 198-222.
  • Emmenegger, Patrick (2010). How Good are Your Counterfactuals? Assessing Quantitative Marco-Comparative Welfare State Research with Qualitative Criteria, Compasss Working Paper 2010-59. (http://www.compasss.org/files/WPfiles/Emmenegger2010a.pdf)
  • Goertz, Gary (2005). Social Science Concepts. A User’s Guide. Princeton: Princeton University Press, pp. 27-68.
  • Goertz, Gary (2006). “Assessing the Trivialness, Relevance, and Relative Importance of Necessary or Sufficient Conditions in Social Science.” Studies in Comparative International Development 41 (2): 88-109.
  • Goertz, Gary and James Mahoney (2006). “A Tale of Two Cultures: Contrasting Quantitative and Qualitative Research”. Political Analysis, 14 (3) 227-249.
  • Hall, Peter (2003). “Aligning Ontology and Methodology in Comparative Research”, in James Mahoney and Dietrich Rueschemeyer (eds.), Comparative Historical Analysis in the Social Sciences. Cambridge: Cambridge University Press, pp. 373-404.
  • Klir, George J., Ute St. Clair and Bo Yuan (1997). Fuzzy Set Theory. Foundations and Applications. Upper Saddle River (NJ): Prentice Hall PTR, pp. 1-9, 47-72, 90-95.
  • Lieberson, Stanley (1991). “Small N’s and Big Conclusions: An Examination of the Reasoning in Comparative Studies Based on a Small Number of Cases”. Social Forces 70 (2): 307-320.
  • Mahoney, James (2003). “Strategies of Causal Assessment in Comparative Historical Analysis”, in James Mahoney and Dietrich Rueschemeyer (eds.), Comparative Historical Analysis in the Social Sciences. Cambridge: Cambridge University Press, pp. 337-372.
  • Ragin, Charles C. (1987). The Comparative Method. Moving Beyond Qualitative and Quantitative Strategies. Berkeley et al.: University of California Press, pp. 85-124, 164-171.
  • Ragin, Charles C. (2000). Fuzzy-Set Social Science. Chicago and London: The University of Chicago Press, pp. 149-202.
  • Ragin, Charles C. (2004). “Turning the Tables: How Case-Oriented Research Challenges Variable-Oriented Research”, in Henry E. Brady and David Collier (eds.), Rethinking Social Inquiry. Lanham et al.: Rowman & Littlefield, pp. 123-138.
  • Ragin, Charles C. (2006). “Set Relations in Social Research: Evaluating Their Consistency and Coverage.” Political Analysis 14 (3): 291-310.
  • Ragin, Charles C. (2008). Redesigning Social Inquiry. Fuzzy Sets and Beyond. Chicago and London: The University of Chicago Press, pp. 1-105, 124-175.
  • Ragin, Charles C. (2008). User’s Guide to Fuzzy-Set / Qualitative Comparative Analysis. Typescript (http://www.u.arizona.edu/~cragin/fsQCA/download/fsQCAManual.pdf)
  • Ragin, Charles C. (2009). “Qualitative Comparative Analysis Using Fuzzy Sets (fsQCA)”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 87-121.
  • Rihoux, Benoît and Gisèle De Meur (2009). “Crisp-Set Qualitative Comparative Analysis (csQCA)”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 33-68.
  • Rihoux, Benoît, Charles C. Ragin, Sakura Yamasaki and Damien Bol (2009). “Conclusions – The Way(s) Ahead”, in Benoît Rihoux and Charles C. Ragin (eds.), Configurational Comparative Methods. Qualitative Comparative Analysis (QCA) and Related Techniques. Los Angeles et al.: Sage, pp. 167-177.
  • Schneider, Carsten Q. and Bernard Grofman (2009). "An Introduction to Crisp-Set QCA, with a Comparison to Binary Logistic Regression". Political Research Quarterly, 62, 4: 662-672
  • Schneider, Carsten Q. und Claudius Wagemann (2006). “Reducing Complexity in Qualitative Comparative Analysis (QCA): Remote and Proximate Factors and the Consolidation of Democracy”. European Journal of Political Research, 45, 5: 751-786.
  • Schneider, Carsten Q. and Claudius Wagemann (2010). “Standards of Good Practice in Qualitative Comparative Analysis (QCA) and Fuzzy Sets”. Comparative Sociology, 9 (3) 397-418.
  • Wagemann, Claudius and Carsten Q. Schneider (2010). “Qualitative Comparative Analysis (QCA) and Fuzzy Sets: the Agenda for a Research Approach and a Data Analysis Technique”. Comparative Sociology, 9 (3) 376-396.

 

The lecturer

Claudius Wagemann works as a lecturer at the Istituto italiano di scienze umane (SUM), Florence, and as an adjunct professor at the Florence campus of New York University (NYU). He took his undergraduate degree from the University of Konstanz and received his Ph.D. from the European University Institute (EUI).

He will publish in due course, together with Carsten Q. Schneider, a textbook on set-theoretical methods and QCA with Cambridge University Press. This is an updated and extended version of their German book (2007, with Barbara Budrich). Furthermore, Wagemann authored, together with Joachim Blatter and Frank Janning, a textbook on qualitative methods in political science.

Apart from his methodological interest, he has been working on various aspects of comparative politics and democracy studies. In 2011, his book on ‘Private Interest Governance Between Breakdown and Change’ will be published with Routledge. Apart from this topics, located between policy analysis, governance studies, interest group research, and organizational sociology, he has also been working on political parties and social movements.

He is currently studying the quality of democracy in advanced (European) democracies, above all, with regard to issues of responsiveness, political competition, political participation, and political attitudes. With regard to this topic, a collaboration with the EUDO (European Union Democracy Observatory) project at the European University Institute is foreseen.

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Tags: Sociology, Political Science, QCA, PhD, Research Methods, Comparative Methods
Published Aug. 24, 2011 2:20 PM - Last modified Aug. 24, 2011 2:36 PM