Aspen Chen is a doctoral candidate in sociology at the University of Connecticut. His primary research areas are education, immigration, and social stratification. He is currently completing his dissertation on early educational trajectories of U.S. immigrant children. The statistical programs that Aspen uses include Stata, R, SPSS, SAS, and M-Plus. His Stata routine, available at the Statistical Software Components (SSC) repertoire, calculates quasi-variances.

Roberto Ferrer is an economist with a general interest in computer programming and a particular interest in statistical programming. He has developed his professional career in central banking, contributing with his research in the Bureau of Economic Research at Venezuela's Central Bank. He uses Stata on a daily basis and contributes regularly to Statalist, a forum moderated by Stata users and maintained by StataCorp. He is also a regular at Stack Overflow, where he answers questions under the Stata tag.

Levicatus Mugenyi is a Ugandan, who was born in the Rakai district. He has 9 years of experience in handling health research data. He started his professional career as a data manager in 2005 after successfully completing his bachelor's degree in statistics from Makerere University Kampala, Uganda. In 2008, he was awarded a scholarship by the Flemish government to undertake a master's degree in biostatistics from Hasselt University, Belgium. After successfully completing the master's program with a distinction, he rejoined Infectious Diseases Research Collaboration (IDRC) and Uganda Malaria Surveillance Project (UMSP) as a statistician in 2010. In 2013, he was awarded an ICP PhD sandwich scholarship on a research project titled Estimation of infectious disease parameters for transmission of malaria in Ugandan children. His research interests include stochastic and deterministic modeling of infectious diseases, survival data analysis, and longitudinal/clustered data analysis. In addition, he enjoys teaching statistical methods. He is also a director and a senior consultant at the Levistat statistical consultancy based in Uganda. His long-term goal is to provide evidence-based information to improve the management of infectious diseases, including malaria, HIV/AIDS, and tuberculosis, in Uganda as well as Africa.

He is currently employed at Hasselt University, Belgium. He was formerly employed (part time) at Infectious Diseases Research Collaboration (IDRC), Kampala, Uganda. He owns a company called Levistat Statistical Consultancy, Uganda.