William W.S. Wei

Profile Picture of William W.S. Wei

William W.S. Wei

  • Fox School of Business and Management

    • Statistics, Operations, and Data Science

      • Professor


Dr. Wei is Professor of Statistics and former Director of Graduate Programs in Statistics at Temple University in Philadelphia, PA. He has been on the faculty since 1974. He earned his B.A. in Economics from the National Taiwan University (1966), B.A. in Mathematics from the University of Oregon (1969), and M.S. (1972) and Ph.D. (1974) in Statistics from the University of Wisconsin, Madison. From 1982-87, he was the Chair of the Department of Statistics at Temple University. He has been a Visiting Professor at many universities including Nankai University in China, National University of Colombia in Colombia, National Sun Yat-Sen University, National Chiao Tung University, and National Taiwan University in Taiwan.

His research interests include time series analysis, forecasting methods, statistical modeling, and their applications. He has developed new methodology in seasonal adjustment, aggregation and disaggregation, outlier detection, robust estimation, and multivariate time series analysis. Some of his most significant contributions include extensive research on the effects of aggregation, methods of measuring information loss due to aggregation, new stochastic procedures of performing data disaggregation, model-free outlier detection techniques, robust methods of estimating autocorrelations, statistics for analyzing multivariate time series, and dimension reduction for high dimensional time series. His first book, Time Series Analysis–Univariate and Multivariate Methods, the first edition published in 1990 and the second edition published in 2006, has been translated into several languages and heavily cited by researchers worldwide. His second book, Multivariate Time Series Analysis and Applications, 1st Edition, was published in 2019 by John Wiley and Sons, Inc.

He is an active educator and researcher. He has successfully supervised many Ph.D. students, who hold teaching positions at universities or leadership positions in government and industry throughout the world. He is a Fellow of the American Statistical Association, a Fellow of the Royal Statistical Society, and an Elected Member of the International Statistical Institute. He was the 2002 President of ICSA (International Chinese Statistical Association). He is currently an Associate Editor of the Journal of Forecasting and the Journal of Applied Statistical Science. In addition to teaching and research, he is also active in community service. He served on the educational advisory committee of local school districts, as the chair of the selection committee for a community high school scholarship program, and as the president of several community organizations, including the Taiwanese Hakka Associations of America. Among the many awards he has received are the 2014 Lifetime Achievement Award and the 2016 Musser Award for Excellence in Research from the Temple University Fox School of Business.

Research Interests

  • Aggregation effects
  • Time unit selection
  • Multivariate GARCH
  • Repeated measurements
  • Space-time modelling
  • High dimension reduction in multivariate time series analysis

Courses Taught




STAT 2103

Statistical Business Analytics


STAT 8123

Time Series Analysis and Forecasting


Selected Publications


  • Nargunam, R., Wei, W.W., & Anuradha, N. (2023). Analyses of the impact of country specific macro risk variables on gold futures contract and its position as an asset class: evidence from India. Statistics and Its Interface, 16(1), 57-67. International Press of Boston. doi: 10.4310/21-sii697.

  • Nargunam, R., Wei, W., & Anuradha, N. (2021). Investigating seasonality, policy intervention and forecasting in the Indian gold futures market: a comparison based on modeling non-constant variance using two different methods. Financial Innovation, 7(1). doi: 10.1186/s40854-021-00283-9.

  • Gehman, A.J. & Wei, W.W. (2021). Testing for poolability of the space-time autoregressive moving-average model. Communications in Statistics - Theory and Methods, 50(20), 4787-4808. Informa UK Limited. doi: 10.1080/03610926.2020.1725052.

  • Lee, B. & Wei, W. (2021). The use of temporally aggregated data in modeling and testing a variance change in a time series. Communications in Statistics: Simulation and Computation. doi: 10.1080/03610918.2021.1928197.

  • Gehman, A. & Wei, W. (2020). Optimal spatial aggregation of space–time models and applications. Computational Statistics and Data Analysis, 145. doi: 10.1016/j.csda.2020.106913.

  • Wei, W.W. (2019). Dimension Reduction in High Dimensional Multivariate Time Series Analysis. In Contemporary Biostatistics with Biopharmaceutical Applications (pp. 33-59). doi: 10.1007/978-3-030-15310-6_3.

  • Wei, W. (2019). Multivariate time series analysis and applications. doi: 10.1002/9781119502951.