Profile

Current Affiliation

Ryosuke Igari (Ph.D.)

Associate Professor, Faculty of Business and Commerce／Graduate School of Business and Commerce, Keio University

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

Research Interest

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

• Business Statistics

• Bayesian Statistics

• Survival Analysis

Publications

Refereed Articles

1. 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).

2. 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).

3. 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).

4. Ryosuke Igari and Makito Takeuchi (in press). “A Dynamic Model for Ranking-Based Conjoint Analysis with No-Choice Options”. Behaviormetrika, 50(1), 263–286. 

5. 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). 

6. 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. 

7. 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. 

8. 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).

9. 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). 

10. 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 / Working Paper

1. Ryosuke Igari and Takahiro Hoshino (2021). “A Data Fusion Approach for Interpurchase Timing Models Using Incomplete Purchase Histories”. SSRN Working Paper Series, 3803078.

2. 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).

3. 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).

4. 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).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).

5. 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).

6. 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).