Gilbert Ritschard

Gilbert Ritschard (born March 24, 1950) is a Swiss statistician specialized in quantitative methods for the social sciences and in the analysis of longitudinal data describing life courses. He is Professor Emeritus at the University of Geneva. He earned a Ph.D. in Econometrics and Statistics at the University of Geneva in 1979. His main contributions are in sequence analysis. He initiated and led the SNFS project that developed the TraMineR R toolkit for sequence analysis. He is one of the founders of the Sequence Analysis Association, which he served as first president.

Scholarly career Gilbert Ritschard graduated in 1973 in quantitative economics, earned a diploma in econometrics in 1975, and his Ph.D. in econometrics and statistics in 1979, all at the Department of Econometrics of the University of Geneva. In his doctoral dissertation titled (in French) [Contributions to the analysis of the qualitative structures of economic models], he developed powerful algorithms for solving qualitative systems of linear equations, i.e., systems where only the sign of the coefficients are known. Such qualitative systems (introduced by Paul Samuelson in his Foundations of Economic Analysis) are of special interest in comparative static analysis. During his time as a student, he served as teaching and research assistant at the Department of Econometrics.

After his Ph.D., Gilbert Ritschard worked during a few months at the United Nations Conference on Trade and Development (UNCTAD) where he participated at the development of a large-scale economic model (see thesis Regression diagnostics Path analysis Data mining Tree methods Life course Sequence analysis: exploration, clustering, and visualization, measures of dissimilarities, representative sequences, probabilistic suffix trees, sequence indicators, multidomain/multichannel analysis, possible impact of timing errors