Louis T. Mariano

Louis T. Mariano
Senior Statistician
Washington Office


Ph.D. in statistics, Carnegie Mellon University; M.S. in statistics, Carnegie Mellon University; B.S. in mathematics and statistics, American University


Lou Mariano is a senior statistician at the RAND Corporation. His current research includes topics in education, military manpower, and healthcare.

Mariano's education research has focused on evaluations of the implementation and efficacy of school reform efforts; furthering the methodology and application of experimental and quasi-experimental designs; refining methods for estimating teacher contributions to student learning; and the expansion of item response theory models, with emphasis on the reduction of measurement error. His current military manpower research includes investigation of factors impacting the dynamics of career path selection, promotion, retention, and diversity of Air Force personnel.

Mariano holds a Ph.D. in statistics from Carnegie Mellon University.

Recent Projects

  • Evaluation of the 4-Day School Week
  • Using Student Achievement Data to Monitor Progress and Performance: Methodological Challenges Presented by COVID-19
  • Data-Enabled Talent Management through Targeted Benchmarks, Best Practices, and Partnerships
  • Evaluation of the Long‐Term Effects of Retention under New York City's Student Promotion Policy
  • Post-operative Nudges to Reduce Opioid Prescribing (POST-OP)

Selected Publications

Kilburn, M. Rebecca, Andrea Phillips, Celia J. Gomez, Louis T. Mariano, Christopher Joseph Doss, Wendy M. Troxel, Emily Morton, and Kevin Estes, Does Four Equal Five? Implementation and Outcomes of the Four-Day School Week, RAND Corporation (RR-A373-1), 2021

Schweig, Jonathan, Andrew McEachin, Megan Kuhfeld, Louis T. Mariano, and Melissa Kay Diliberti, Adapting Course Placement Processes in Response to COVID-19 Disruptions: Guidance for Schools and Districts, RAND Corporation (RR-A1037-1), 2021

Mariano, L.T. and Martorell, P., "The Causal Effects of Grade Retention on Behavioral Outcomes," Journal of Research on Educational Effectiveness , 11(2), 2018

Mariano, L.T. and Elliott, M.N., "An Item Response Theory Approach to Estimating Survey Mode Effects: Analysis of Data from a Randomized Mode Experiment," Journal of Survey Statistics and Methodology, 5(2), 2017

Lim, Nelson, Louis T. Mariano, Amy G. Cox, David Schulker, and Lawrence M. Hanser, Improving Demographic Diversity in the U.S. Air Force Officer Corps, RAND Corporation (RR-495-AF), 2014

Mariano, Louis T. and Martorell, Paco, "The Academic Effects of Summer Instruction and Retention in New York City," Educational Evaluation and Policy Analysis, 35, 2013

Mariano, L.T., McCaffrey, D.F., and Lockwood, J.R., "A Model For Teacher Effects From Longitudinal Data Without Assuming Vertical Scaling," Journal of Educational and Behavioral Statistics, 35, 2010

Mariano, L.T. and Junker, B.W., "Covariates of the Rating Process in Hierarchical Models for Multiple Ratings of Test Items," Journal of Educational and Behavioral Statistics, 32(3), 2007

Honors & Awards

  • Fellow, American Statistical Association
  • Leonard J. Savage Award for Outstanding Doctoral Dissertation in the Application Methodology of Bayesian Statistics, The International Society for Bayesian Analysis & the American Statistical Association Section on Bayesian Statistical Science
  • Outstanding Reviewer, Journal of Educational and Behavioral Statistics (2005, 2009, 2013 and 2014), American Educational Research Association


  • Education Policy

    Can Grade Retention Help with COVID-19 Learning Recovery in Schools?

    Early grade retention is getting more attention as a potential way to make up for missed learning during the pandemic. But retaining kids without providing the necessary supports or failing to identify the right kids using objective criteria will likely yield ineffective results or even lead to adverse effects.

    Mar 28, 2023

    Brookings Institution's Brown Center Chalkboard