Current Affiliation
Ryosuke Igari (Ph.D.)
Associate Professor, Faculty of Business and Commerce／Graduate School of Business and Commerce, Keio University
E-mail: igari[at]fbc.keio.ac.jp ※Replace [at] with @
Professional Employment
April, 2018～March, 2020 Lecturer, Faculty of Business Administration, Hosei University
April, 2020～March, 2024 Associate Professor, Faculty of Business Administration／Graduate School of Business Administration, Hosei University
April, 2024～ Associate Professor, Faculty of Business and Commerce／Graduate School of Business and Commerce, Keio University
Marketing Science
Brand Choice Model and Interpurchase-Timing Model
Modeling Consumers' Behavior on Online and Offline Channels
Conjoint Analysis
Understanding Consumers' Behavior of Internet Browsing
Advertising Theory
Measuring Advertising Effects
Quantitative Analysis for TV-CM Creatives
Models for Media and Adverting Planning
Quantitative Analysis of Media Usage Behavior
Statistical Science
Bayesian Statistics
Discrete Choice Model
Survival Analysis
Business Statistics
Refereed Articles
Ryosuke Igari (2025). Modelling Viewing Patterns of Serial TV Dramas Considering Live Viewing and Time Shifting. Journal of Choice Modelling, 55(100548), 1-16.
Makito Takeuchi and Ryosuke Igari (2023). Changes of consumers' media exposure before and after the COVID-19 epidemic and exploratory study using individual personality traits. JSMD Review, 8(1), 1-11. (in Japanese).
Ryosuke Igari and Makito Takeuchi (2023). Threats of COVID-19 and Changes in Consumers' Media Usage Behavior－ Understanding Dynamic Change of Segments－. Communications of the Operations Research Society of Japan, 68(3), 138-146. (in Japanese).
Ryosuke Igari and Takahiro Hoshino (2023). Modeling Interpurchase-Timing Using Competing Risk Model Incorporating Dynamic Frailty: Application to Consumers' Purchase Behavior on Multi-Channel. Journal of the Japan Statistical Society: Series J, 52(2), 269-293. (in Japanese).
Ryosuke Igari and Makito Takeuchi (in press). A Dynamic Model for Ranking-Based Conjoint Analysis with No-Choice Options. Behaviormetrika, 50(1), 263–286.
Makito Takeuchi and Ryosuke Igari (2021). Prediction of Consumers' Purchase Behavior by Conjoint Analysis Considering Context Effects. Japan Society of Marketing and Distribution, 24(2), 17-32. (in Japanese).
Ryosuke Igari and Takahiro Hoshino (2018). A Bayesian Data Combination Approach for Repeated Durations under Unobserved Missing Indicators: Application to Interpurchase-Timing in Marketing. Computational Statistics & Data Analysis, 126, 150-166.
Ryosuke Igari and Takahiro Hoshino (2017). A Survival Analysis Incorporating Auxiliary Information by a Bayesian Generalized Method of Moments: Application to Purchase Duration Modeling. Journal of the Japanese Society of Computational Statistics, 30 (1), 27-44.
Ryosuke Igari and Takahiro Hoshino (2016). A Joint Model of Consumer's Interpurchase-Timing and Purchase Amounts in Online-Offline Channels. Communications of the Operations Research Society of Japan, 61, 589-599. (in Japanese).
Ryosuke Igari and Takahiro Hoshino (2014). A Joint Analysis of Acquiring Visitors and Website Usage Behavior Using Hierarchical Bayes Dynamic Sample Selection Model. Journal of the Japan Statistical Society: Series J, 43, 185-214. (in Japanese).
Ryosuke Igari and Takahiro Hoshino (2012). A Hierarchical Bayes Adoption and Diffusion Model for Multiple Websites Using the Individual-Level Longitudinal Web Access Data. Japanese Journal of Marketing Science, 20, 43-67. (in Japanese).
Non-Refereed Articles
Makito Takeuchi and Ryosuke Igari (in press). Effects of Information-Processing on Responses to Conjoint Measurement: An Explanatory Study Using Personality Traits Based on Dual-Process Theory. Oikonomika (in Japanese).
Ryosuke Igari (2019). A View of Interpurchase-Timing Model in Marketing: Empirical Analysis Using Bayesian Modeling. The Hosei Journal of Business, 57(3), 1-17 (in Japanese).
Ryosuke Igari and Takahiro Hoshino (2016). Estimation of the Effects of Advertising and Price Promotion Using Statistical Data Fusion. Bulletin of Nikkei Advertising Research Institute, 289, 2-9 (in Japanese).
Isa Katayanagi and Ryosuke Igari (2014). Classification of TV-CM Creatives and Advertising Effects: Comparison by Brand Penetration. Bulletin of Nikkei Advertising Research Institute, 276, 18-25 (in Japanese).
Ryosuke Igari and Tatsuya Kawahara (2014). Evaluating Advertising Campaign Considering Cross-Media Effects: Modeling the Effects of Advertising Recognition and Attitude Change. Bulletin of Nikkei Advertising Research Institute, 274, 24-30 (in Japanese).
Working Paper
Ryosuke Igari and Takahiro Hoshino (2021). A Data Fusion Approach for Interpurchase Timing Models Using Incomplete Purchase Histories. SSRN Working Paper Series, 3803078.
Ryosuke Igari and Takahiro Hoshino (2017). Semiparametric Quasi-Bayesian Inference with Dirichlet Process Priors: Application to Nonignorable Missing Responses. Keio-IES- Discussion Paper Series (2017/06).
Takahiro Hoshino and Ryosuke Igari (2017). Quasi-Bayesian Inference for Latent Variable Models with External Information: Application to Generalized Linear Mixed Models for Biased Data. Keio-IES- Discussion Paper Series (2017/04).
Presentation (Selected)
Ryosuke Igari and Makito Takeuchi (2025) Conjoint Analysis Considering Phantom Alternatives. Informs Marketing Science Conference 2025 (The Westin Washington DC Downtown; June 14th, 2025)
Ryosuke Igari and Takahiro Hoshino (2019). A Data Fusion Approach for Interpurchase-Timing Model Using the Incomplete Purchase Histories. INFORMS Marketing Science Conference 2019 (University of Roma Tre; June 22th, 2019).