Greg Ridgeway

Last updated: January 2026

Rebecca W. Bushnell Professor of Criminology
Department of Criminology
Department of Statistics and Data Science
University of Pennsylvania – Philadelphia, PA
(215) 573-9109 · gridge@upenn.edu

Education

Professional Experience

  • 8/2014-present, Department of Criminology and Department of Statistics and Data Science, University of Pennsylvania

  • 1/2021-12/2025, Co-editor-in-chief, Journal of Quantitative Criminology

  • 7/2012-7/2014, National Institute of Justice, U.S. Department of Justice
    Directed the Department of Justice’s science agency (approximately 80 staff; $250M/year), advancing science and innovation in forensics, technology, and social science

    • Acting Director (1/2013-7/2014)
    • Deputy Director, Senior Executive Service (7/2012-7/2014)

  • 7/2000-6/2012, RAND Corporation
    Led a major research portfolio on policing, courts, corrections, gangs, guns, drugs, and justice policy (approximately 50-person research team; ~40 proposals/year; ~$10M/year projects)

    • RAND Safety & Justice Program, Director (1/2009-6/2012)
    • RAND Center on Quality Policing, Director (1/2008-6/2012)
    • RAND Safety & Justice Program, Acting Director (11/2007-1/2009)
    • RAND Statistics Group, Senior Statistician (5/2007-6/2012)
    • RAND Safety & Justice Program, Associate Director (8/2006-11/2007)
    • [RAND Statistics Group](https://www.rand.org/statistics.html, Full Statistician (5/2003-5/2007)
    • [RAND Statistics Group](https://www.rand.org/statistics.html, Associate Statistician (7/2000-5/2003)

  • 7/2001-8/2001, Department of Sociology, University of Washington – Visiting Scholar

  • 9/1999-6/2000, Department of Statistics, University of Washington – Lecturer

  • 6/1996-9/1997, Microsoft Research – Research assistant

  • 9/1993-9/1995, California Department of Mental Health, Atascadero State Hospital – Research assistant (Clinical Safety Project)

  • 8/1994-9/1995, UC Berkeley Cooperative Extension – Research assistant (Integrated Hardwood Range Management Program)

University Service

  • 2021-present, Co-director, Data Driven Discovery Initiative
    Launched a new data science initiative; staffing; post-doc program; data science for social good; seed grants; data science minor (with Bhuv Jain)

  • 2022-present, Committee member, Senate Committee on Students and Educational Policy
    Advises on admissions, instruction, academic integrity, teaching evaluation, grading policies, student records, disciplinary systems, and campus environment

  • 2019-2025, Chair, Department of Criminology
    Stimulated grant- and donor-funded research (especially Philadelphia justice policy analysis); secured strategic senior hires; seeded crime policy lab

  • 2021-2024, Committee member, Committee on Planning and Priorities
    Advises SAS on emerging issues in education, research, and operations

  • 2019-2021, SAS Data Driven Discovery Working Group
    Strategic planning on hiring, programming, data science coverage, and new opportunities

  • 2014-2023, Director, Master of Science in Criminology program
    Admissions; career planning; alumni network; placements; joint programs (Fels, SP2, Law)

  • 2018-2022, Committee member, Committee on Undergraduate Education
    Advises Dean and faculty on SAS undergraduate educational mission

  • 2018-2020, Committee member, Vice Provost for Education Fellowship Selection Committee
    Selects nominees for limited-submission fellowships

Awards

  • 2025, Fellow, American Society of Criminology
  • 2024, Fellow, Academy of Experimental Criminology
  • 2013, Fellow, American Statistical Association
  • 2007, American Statistical Association Outstanding Statistical Application Award (with J. Grogger) for “Testing for racial profiling in traffic stops from behind a veil of darkness.”
    RAND Gold Medal Award for contributions advancing RAND’s mission.
  • 2005, Commendation by ATF Los Angeles Field Division and the Attorney General of California for contributions to reducing firearms-related crimes in Los Angeles.
    RAND President’s Choice Award for developing pioneering methods for racial profiling.
  • 1999, Z.W. Birnbaum Award (UW Department of Statistics) for excellence in research and presentation.

Patent Awards

  • 2014
    – US Patent 8,719,210: “System and Method for Medical Treatment Hypothesis Testing.” Granted May 6, 2014
  • 2013
    – US Patent 8,538,906: “System and method for medical treatment hypothesis testing using relative likelihood of treatment results.” Granted September 17, 2013
  • 2003
    – US Patent 6,606,613: “Methods and apparatus for using task models to help computer users complete tasks.” Granted August 12, 2003
  • 2001
    – US Patent 6,330,554: “Methods and apparatus using task models for targeting marketing information to computer users based on a task being performed.” Granted December 11, 2001
    – US Patent 6,195,622: “Methods and apparatus for building attribute transition probability models for use in pre-fetching resources.” Granted February 27, 2001
  • 2000
    – US Patent 6,154,767: “Methods and apparatus for using attribute transition probability models for pre-fetching resources.” Granted November 28, 2000
    – US Patent 6,088,718: “Methods and apparatus for using resource transition probability models for pre-fetching resources.” Granted July 11, 2000
    – US Patent 6,012,052: “Methods and apparatus for building resource transition probability models for use in pre-fetching resources, editing resource link topology, building resource link topology templates, and collaborative filtering.” Granted January 4, 2000

Grants and Contracts

  • 2020-2023 – Principal Investigator, “Prosecutors and Criminal Justice Reform: Independent Research Partnership with the Philadelphia District Attorney’s Office,” Arnold Ventures, $2,509,009 (with Aurélie Ouss)
  • 2020-2022 – Co-Principal Investigator, “Evaluation of Philadelphia Group Violence Intervention,” Urban Affairs Coalition and Philadelphia Office of Violence Prevention, $150,269 (with Ruth Moyer)
  • 2020-2022 – Principal Investigator, “Crime Prevention Through Intelligence & Information Sharing,” Neubauer Family Foundation, $543,298 (with Aaron Chalfin)
  • 2016 – Site PI, “Disrupting Illegal Gun Transfers,” NIJ (prime: RAND), 2013-R2-CX-0016, $42,118
  • 2015-2016 – Site PI, “Replication of the Cardiff Violence Prevention Model in the United States,” RWJF (prime: NFCDC&PI), Grant 72352, $213,572
  • 2011-2012 – Program Director, “Developing the Center of Research and Security Studies,” Ministry of Interior, Abu Dhabi, $1,500,000
  • 2010-2012 – Co-PI, “NLECTC Information and Geospatial Technology Center of Excellence,” NIJ 2010-IJ-CX-K007, $6,000,000 (with John Hollywood)
  • 2010-2012 – Co-PI, “Experimental Evaluation of the BJA DMI Training and Technical Assistance Initiative,” BJA 2010-DJ-BX-1672, $2,900,000 (with Beau Kilmer and Jessica Saunders)
  • 2010-2012 – Co-PI, “Enabling the Police to Serve the Needs of 21st Century Israel,” Israel Ministry of Public Security and RAND Israel Policy Fund, $1,600,000 (with Steven Popper)
  • 2010-2012 – Principal Investigator, “Predictive Policing Analytic and Evaluation Research Support,” NIJ 2009-IJ-CX-K114, $1,084,846
  • 2008-2010 – Principal Investigator, “Case weighting for federal public defender services,” AOUSC USCA08F0404, $564,510 (with Nick Pace)
  • 2008-2012 – Principal Investigator, “Evaluation of the Los Angeles County Juvenile Justice Crime Prevention Act Programs,” LA County Probation, $1,610,000 (with Terry Fain and Susan Turner)
  • 2008 – Principal Investigator, “Development of internal benchmarking system,” New York City Police Foundation, $32,000
  • 2007 – Principal Investigator, “Assessment of racial bias in NYPD stop, question, and frisk practices,” New York City Police Foundation, $120,000
  • 2007-2008 – Principal Investigator, “Strategies for improving police recruiting,” San Diego Police Department, $160,000
  • 2006-2007 – Co-PI, “Analysis of Graduate Driver Licensing - Lower Risk Exposure or Better Driving?,” NICHD 1R03HD052547-01, $184,122 (with Pinar Karaca-Mandic)
  • 2004-2009 – Principal Investigator, “Improving Police-Community Relations in Cincinnati,” City of Cincinnati 45X0028, $1,581,300
  • 2002-2004 – Principal Investigator, “DOJ Racial Profiling Initiative,” City of Oakland EM3.20.02, $75,000
  • 2001-2008 – Co-PI, “Strategic Disruption of Firearms Markets,” NIJ 2001-IJ-CX-0028, $647,952 (with George Tita)
  • 2001-2002 – Principal Investigator, “Data mining and Columbia counterdrug strategies,” Office of the Secretary of Defense (three projects) $57,845, $27,965, $19,165

Publications

Working papers

G. Ridgeway and C. Loeffler (2027). “Crime Statistics,” Annual Review of Statistics and Its Applications, 14.

J.R. Gyourko and G. Ridgeway. “Safeguarding the Credit Records of Youth in Foster Care: What Interventions Reduce Risk of Child Identity Fraud?”

R. Hester, G. Ridgeway, and R. Labrecque. “Fairness Regularized Risk Assessment Models: Balancing Risk Prediction with Racial and Ethnic Equality”

Peer-reviewed articles

G. Ridgeway (to appear). “A Conditional Ordinal Stereotype Model to Estimate Police Officers’ Propensity to Escalate Force,” Journal of the American Statistical Association. (Data and code) (Supplemental appendix) (Additional mathematical details)

F.A. Amaral, C. Loeffler, and G. Ridgeway (2024). “Prosecutorial discretion not to invoke the criminal process and its impact on firearm cases,” Journal of Criminal Justice, 95:102313.

J.R. Gyourko and G. Ridgeway (2024). “Predictors of Identity Fraud Victimization of Adolescent Youth in Foster Care,” Victims & Offenders.

V. Nguyen and G. Ridgeway (2023). “Judges on the Benchmark: Developing a Sentencing Feedback System,” Justice Quarterly, 41(1):1-37.

E.C. South, J.M. MacDonald, V.W. Tam, G. Ridgeway, and C.C. Branas (2023). “Effect of Abandoned Housing Interventions on Gun Violence, Perceptions of Safety, and Substance Use in Black Neighborhoods: A Citywide Cluster Randomized Trial,” JAMA Internal Medicine 183(1):31-39.

Z. F. Meisel, F. Shofer, A. Dolan, E. B. Goldberg, K. V. Rhodes, E. P. Hess, V. R. Bellamkonda, J. Perrone, C. C. Cannuscio, L. Becker, M. A. Rodgers, M. M. Zyla, J. J. Bell, S. McCollum, E. Engel-Rebitzer, M. J. Nguemeni Tiako, G. Ridgeway, and M. M. Schapira (2022). “A multicentered randomized controlled trial comparing the effectiveness of pain treatment communication tools in emergency department patients with back pain or kidney stone pain,” American Journal of Public Health 112(S1):S45-S55.

G. Ridgeway, J. Rosenberger, and L. Xue (2021). “Statisticians Engage in Gun Violence Research,” Statistics and Public Policy 8(1):73-79.

Y. Wu and G. Ridgeway (2021). “Effect of Public Transit on Crime: Evidence from SEPTA strikes in Philadelphia,” Journal of Experimental Criminology 17:267-286.

G. Ridgeway, B. Cave, J. Grieco, and C.E. Loeffler (2021). “A Conditional Likelihood Model of the Relationship Between Officer Features and Rounds Discharged in Police Shootings,” Journal of Quantitative Criminology 37(1):303-326.

R. Moyer and G. Ridgeway (2020). “The Effect of Outpatient Methadone Maintenance Treatment Facilities on Place-Based Crime,” Journal of Experimental Criminology 16(2):227-245.

G. Ridgeway, R. Moyer, and S. Bushway (2020). “Sentencing Scorecards: Reducing Racial Disparities in Prison Sentences at Their Source,” Criminology & Public Policy 19(4):1113-1138.

G. Ridgeway (2020). “The Role of Individual Officer Characteristics in Police Shootings,” The ANNALS of the American Academy of Political and Social Science 687(1):58-66. (technical appendix showing the decomposition of information)

G. Ridgeway, J. Grogger, R.A. Moyer, and J.M. MacDonald (2019). “Effect of Gang Injunctions on Crime: A Study of Los Angeles from 1988-2014,” Journal of Quantitative Criminology 35(3):517-541.

C.E. Loeffler, J.M. Hyatt, and G. Ridgeway (2019). “Measuring Self-Reported Wrongful Convictions Among Prisoners,” Journal of Quantitative Criminology 35(2):259-286.

R. Moyer, J.M. MacDonald, G. Ridgeway, and C. Branas (2019). “Effect of Remediating Blighted Vacant Land on Shootings: A Citywide Cluster Randomized Trial,” American Journal of Public Health 109(1):140-144.

G. Ridgeway, M. Nørgaard, T.B. Rasmussen, W.D. Finkle, L. Pedersen, H.E. Bøtker, and H.T. Sørensen (2019). “Benchmarking Danish Hospitals on Mortality and Readmission Rates After Cardiovascular Admission,” Clinical Epidemiology 11:67-80.

Ridgeway, G. (2019). “Experiments in Criminology,” Annual Review of Statistics and Its Applications, 6:37-61.

O. Mitchell and G. Ridgeway (2018). “Assessing the Fairness and Effectiveness of Bicycle Stops in Tampa,” Police Quarterly 21(4):461-485.

J. Lyons, V. Desai, Y. Xu, G. Ridgeway, W. Finkle, P. Solari, S. Sullivan, S. Lanes (2018). “Development and Validation of an Algorithm for Identifying Patients with Hemophilia A in an Administrative Claims Database,” Value in Health 21(9):1098-1103.

S.F. Jacoby, L.M. Kollar, G. Ridgeway, S.A. Sumner (2018). “Health System and Law Enforcement Synergies for Injury Surveillance, Control and Prevention: A Scoping Review,” Injury Prevention 24:305-311.

V. Bacak and G. Ridgeway (2018). “Availability of Health-Related Programs in Private and Public Prisons,” Journal of Correctional Health Care 24(1):62-70.

S.-L. Faraji, G. Ridgeway, and Y. Wu (2018). “Effect of Emergency Winter Homeless Shelters on Property Crime,” Journal of Experimental Criminology 14(2):129-140.

G. Ridgeway (2018). “Policing in the Era of Big Data,” Annual Review of Criminology, 1:401-419.

R. Umbach, A. Raine, and G. Ridgeway (2017). “Aggression and Lost Sleep: a Daylight Saving Time Natural Experiment,” Journal of Experimental Criminology 13(4):439-453.

G. Ridgeway (2017). “Stop-and-Frisk is Essential… and Requires Restraint,” Journal of Policy Analysis and Management 36(3):683-689 (with discussion and rejoinder).

G. Ridgeway and J.M. MacDonald (2017). “Effect of Rail Transit on Crime: A Study of Los Angeles from 1988-2014,” Journal of Quantitative Criminology 33(2):277-291.

G. Ridgeway and B. Kilmer (2016). “Bayesian inference for the distribution of grams of marijuana in a joint,” Drug and Alcohol Dependence 165:175-180.

G. Ridgeway (2016). “Officer Risk Factors Associated with Police Shootings: A Matched Case-Control Study,” Statistics and Public Policy 3(1):1-6.

G. Ridgeway, S. Kovalchik, B.A. Griffin, and M.U. Kabeto (2015). “Propensity score analysis with survey weighted data,” Journal of Causal Inference 3(2):237-249.

J. Saunders, R. Lundberg, A.A. Braga, G. Ridgeway, and J. Miles (2015). “A Synthetic Control Approach to Evaluating Place-Based Crime Interventions,” Journal of Quantitative Criminology 31(3):413-434.

W.D. Finkle, S. Greenland, G. Ridgeway, J.L. Adams, M.A. Frasco, M.B. Cook, J.F. Fraumeni, R.N. Hoover (2014). “Increased Risk of Non-fatal Myocardial Infarction Following Testosterone Therapy Prescription in Men,” PLOS One 9(1):e85805.

G. Ridgeway and J.M. MacDonald. “A Method for Internal Benchmarking of Criminal Justice System Performance,” Crime & Delinquency 60(1):145-162.

A.A. Braga, G.J. Wintemute, G.L. Pierce, P.J. Cook, and G. Ridgeway (2012). “Interpreting the empirical evidence on illegal gun market dynamics,” Journal of Urban Health 89(5):779-93.

D. Golinelli, G. Ridgeway, H. Rhoades, J. Tucker and S. Wenzel (2012). “Bias and variance trade-offs when combining propensity score weighting and regression: with an application to HIV status and homeless men,” Health Services and Outcomes Research Methodology 12(2-3):104-118.

W.D. Finkle, J.S. Der, S. Greenland, J.L. Adams, G. Ridgeway, T. Blaschke, Z. Wang, R.M. Dell, and K.B. VanRiper (2011). “Risk of Fractures Requiring Hospitalization After an Initial Prescription for Zolpidem, Alprazolam, Lorazepam, or Diazepam in Older Adults,” Journal of the American Geriatrics Society 59(10):1883-1890.

G. Ridgeway, A. Braga, G. Tita, and G. Pierce (2011). “Intervening in gun markets: An experiment to assess the impact of targeted gun law messaging,” Journal of Experimental Criminology 7(1):103-109.

J.M. MacDonald, R.J. Stokes, D. Cohen, A. Kofner, and G. Ridgeway (2010). “The Effect of Light Rail Transit on Body Mass Index and Physical Activity,” American Journal of Preventive Medicine 39(2):105-112.

P. Karaca-Mandic and G. Ridgeway (2010). “Behavioral Impact of Graduated Driver Licensing on Teenage Driving Risk and Exposure,” Journal of Health Economics 29:48-61.

G. Ridgeway and J.M. MacDonald (2009). “Doubly Robust Internal Benchmarking and False Discovery Rates for Detecting Racial Bias in Police Stops,” Journal of the American Statistical Association 104(486):661-668.

R. Lin, T.A. Louis, S.M. Paddock, G. Ridgeway (2009). “Ranking USRDS provider specific SMRs from 1998-2001,” Health Services and Outcomes Research Methodology 9(1):22-38.

R.J. Stokes, J.M. MacDonald, and G. Ridgeway (2008). “Estimating the effects of light rail transit on health care costs,” Health & Place 14(1):45-58.

MacDonald, J.M., R.J. Stokes, G. Ridgeway, and K.J. Riley (2007). “Race, Neighborhood context, and perceptions of injustice by the police,” Urban Studies 44(13):2567-2585.

D.F. McCaffrey, A.R. Morral, and G. Ridgeway, B.A. Griffin (2007). “Interpreting treatment effects when cases are institutionalized after treatment,” Drug and Alcohol Dependence 89(2-3):126-138.

G. Tita and G. Ridgeway (2007). “The impact of gang formation on local patterns and levels of crime,” Journal of Research in Crime and Delinquency 44(2):208-237.

R.N. Bluthenthal, G. Ridgeway, T. Schell, R. Anderson, N.M. Flynn, and A.H. Kral (2007). “Examination of the association between syringe exchange program (SEP) dispensation policy and SEP client-level syringe coverage among injection drug users,” Addiction 102(4):638-646.

R. Boer, Y. Zheng, A. Overton, G. Ridgeway, D. Cohen (2007). “Neighborhood Design and Walking Trips in 10 U.S. Metropolitan Areas,” American Journal of Preventive Medicine 32(4):298-304.

R. Lin, T.A. Louis, S.M. Paddock, and G. Ridgeway (2006). “Loss Function Based Ranking in Two-Stage Hierarchical Models,” Bayesian Analysis 1(4):915-946.

G. Tita, A. Braga, G. Ridgeway, G. Pierce (2006). “The criminal purchase of firearm ammunition in Los Angeles, California,” Injury Prevention 12:308-311.

J. Grogger and G. Ridgeway (2006). “Testing for racial profiling in traffic stops from behind a veil of darkness,” Journal of the American Statistical Association 101(475):878-887. ASA 2007 Outstanding Statistical Application Award

S.M. Paddock, G. Ridgeway, R. Lin, T.A. Louis (2006). “Flexible distributions for triple-goal estimates in two-stage hierarchical models,” Computational Statistics and Data Analysis 50(11):3243-3262.

G. Ridgeway (2006). “Assessing the effect of race bias in post-traffic stop outcomes using propensity scores,” Journal of Quantitative Criminology 22(1):1-29. Example code and dataset.

D.A Cohen, T.A. Farley, K. Mason, and G. Ridgeway (2006). “The collectivity of sexual behaviour,” International Journal of STD & AIDS 17(3):151-156.

C. Guarino, G. Ridgeway, M. Chun, and R. Buddin (2005). “Latent Variable Analysis: A New Approach to University Ranking,” Higher Education in Europe 30(2):147-165. Preprint version

D. McCaffrey, G. Ridgeway, A. Morral (2004). “Propensity score estimation with boosted regression for evaluating adolescent substance abuse treatment,” Psychological Methods 9(4):403-425. [Included in J. Miles and B. Stucky (editors) (2014). Quantitative Psychology, SAGE Publications.]

A.R. Morral, D.F. McCaffrey, G. Ridgeway (2004). “Effectiveness of community-based treatment for substance abusing adolescents: 12-month outcomes from a case-control evaluation of a Phoenix Academy,” Psychology of Addictive Behaviors 18(3):257-268.

G. Ridgeway and D. Madigan (2003). “A sequential Monte Carlo method for Bayesian analysis of massive datasets,” Data Mining and Knowledge Discovery 7(3):301-319.

D. Relles, G. Ridgeway, and G. Carter (2003). “Data mining and the implementation of a prospective payment system for inpatient rehabilitation,” Health Services and Outcomes Research Methodology 3:247-266.

G.M. Carter, D.A. Relles, G. Ridgeway, C.M. Rimes (2003). “Measuring function for Medicare inpatient rehabilitation payment,” Health Care Financing Review 24(3):25-44.

G. Ridgeway and D. Madigan (2002). “Bayesian analysis of massive datasets via particle filters,” Proceedings of the Eighth ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, 5-13.

D. Madigan, N. Raghavan, W. DuMouchel, M. Nason, C. Posse, and G. Ridgeway (2002). “Likelihood-Based Data Squashing: A Modeling Approach to Instance Construction,” Data Mining and Knowledge Discovery 6(2):173-190.

G. Ridgeway (2002). “Looking for Lumps: Boosting and bagging for density estimation,” Computational Statistics and Data Analysis 38(4):379-392. (R script)

D. Rusk, K. Lin, D. Swartz, and G. Ridgeway (2002). “Bayesian Updating of Damage Size Probabilities for Aircraft Structural Life-Cycle Management,” Journal of Aircraft 39(4):689-696.

G. Ridgeway, D. Madigan, T. Richardson, and J. O’Kane (1998). “Interpretable boosted naïve Bayes classification,” Proceedings, Fourth International Conference on Knowledge Discovery and Data Mining (R. Agrawal, P. Stolorz, G. Piatetsky-Shapiro, eds.), 101-104.

Peer-reviewed reports

G. Ridgeway, O. Mitchell, S. Gunderman, C. Alexander, J. Letten (2016). An Examination of Racial Disparities in Bicycle Stops and Citations Made by the Tampa Police Department, COPS-W0801.

T. Fain, S. Turner, and G. Ridgeway (2012). Los Angeles County Juvenile Justice Crime Prevention Act: Fiscal Year 2009-2010 Report, RAND TR-988.

N.M. Pace, G. Ridgeway, J.M. Anderson, C. Fan, M. Horta (2011). Case Weights for Federal Defender Organizations, RAND TR-1007-AOUSC.

T. Fain, S. Turner, and G. Ridgeway (2011). Los Angeles County Juvenile Justice Crime Prevention Act: Fiscal Year 2008-2009 Report, RAND TR-832.

G. Ridgeway, L.W. Castaneda, A.B. Cross, E. Wilke, and J. Saunders (2010). “The Experience of Domestic Agencies: Police, Fire, and Federal Agencies,” in Sexual Orientation and U.S. Military Personnel Policy, RAND MG-1056-OSD. Volume received 2011 Policy Impact Award from the American Association for Public Opinion Research.

L.W. Castaneda and G. Ridgeway (2010). Today’s Police and Sheriff Recruits: Insights from the Newest Members of America’s Law Enforcement Community, RAND MG-992-DOJ.

T. Fain, S. Turner, and G. Ridgeway (2010). Los Angeles County Juvenile Justice Crime Prevention Act: Fiscal Year 2007-2008 Report, RAND TR-746.

G. Ridgeway (2009). Cincinnati Police Department’s Traffic Stops: Applying RAND’s Framework to Analyze Racial Disparities, RAND MG-914-CC.

N. Lim, C. Matthies, G. Ridgeway, B. Gifford (2009). To Protect and to Serve: Enhancing the Efficiency of LAPD Recruiting, RAND MG-881-RMPF. (Nominated by LAPD and received honorable mention from IACP’s Excellence in Law Enforcement Research Award.)

G.F. Treverton, C. Matthies, K.J. Cunningham, J. Goulka, G. Ridgeway, A. Wong (2009). Film Piracy, Organized Crime, and Terrorism, RAND MG-742-MPA.

G. Ridgeway, T.L. Schell, B. Gifford, J. Saunders, S. Turner, K.J. Riley, T.L. Dixon (2009). Police-Community Relations in Cincinnati, RAND MG-853-CC.

G. Ridgeway, N. Lim, B. Gifford, C. Koper, C. Matthies, S. Hajiamiri, A. Huynh (2008). Strategies for Improving Officer Recruitment in the San Diego Police Department, RAND MG-724-SDPD.

B.D. Rostker, L.M. Hanser, W.M. Hix, C. Jensen, A.R. Morral, G. Ridgeway, T.L. Schell (2008). Evaluation of the New York City Police Department Firearm Training and Firearm-Discharge Review Process, RAND MG-717-NYPD.

G. Ridgeway, G.L. Pierce, A.A. Braga, G. Tita, G. Wintemute, W. Roberts (2008). Strategies for Disrupting Illegal Firearm Markets: A Case Study of Los Angeles, RAND TR-512-NIJ.

G. Ridgeway (2007). Analysis of Racial Disparities in the New York Police Department’s Stop, Question, and Frisk Practices, RAND TR-534-NYCPF.

T.L. Schell, G. Ridgeway, T.L. Dixon, S. Turner, K.J. Riley (2007). Police-Community Relations in Cincinnati: Year Three Evaluation Report, RAND TR-535-CC.

G. Ridgeway, T. Schell, K.J. Riley, S. Turner, T.L. Dixon (2006). Police-Community Relations in Cincinnati: Year Two Evaluation Report, RAND TR-445-CC.

A.R. Morral, D.F. McCaffrey, G. Ridgeway, A. Mukherji, C. Beighley (2006). The Relative Effectiveness of 10 Adolescent Substance Abuse Treatment Programs in the United States, TR-346.

K. Jack Riley, S. Turner, J. MacDonald, G. Ridgeway, T. Schell, J. Wilson, T.L. Dixon, T. Fain, D. Barnes-Proby, and B. Fulton (2005). Police-Community Relations in Cincinnati, RAND TR-333.

K.J. Riley, N. Rodriguez, G. Ridgeway, D. Barnes-Proby, N. Griffith Forge, V. Webb (2005). Just Cause or Just Because? Prosecution and Plea-Bargaining Resulting in Prison Sentences on Low-Level Drug Charges in California and Arizona, RAND MG-288-RWJ.

D.A. Relles, G. Ridgeway, G.M. Carter, M. Beeuwkes Buntin (2005). Possible Refinements to the Construction of Function-Related Groups for the Inpatient Rehabilitation Facility Prospective Payment System, TR-207-CMS.

L.M. Davis, K.J. Riley, G. Ridgeway, J.E. Pace, S. Cotton-Nelson, P. Steinberg, K. Damphousse, and B.L. Smith (2004). When Terrorism Hits Home: How Prepared Are State and Local Law Enforcement?, RAND MG-104-MIPT. Download research brief (pdf)

G. Ridgeway, K.J. Riley, J. Grogger (2004). Analysis of Oakland’s stop and search data, Chapter 9 in Promoting Cooperative Strategies to Reduce Racial Profiling, Oakland Police Department.

G. Tita, K.J. Riley, G. Ridgeway, C. Grammich, A.F. Abrahamse, and P. Greenwood (2003). Reducing Gun Violence in East Los Angeles: Results from an Intervention, RAND MR-1764-NIJ. (Listed in the 2004 guide of University Press Books Selected for Public and Secondary School Libraries.)

L.J. Hickman, T. Fain, S. Turner, G.K. Ridgeway, B. Raymond, and J.R. Lockwood (2003). Evaluation of the Impact of Seattle’s DWLS Impound Law, WR-117-SEA.

G.M. Carter, M. Beeuwkes Buntin, O. Hayden, S.M. Paddock, D.A. Relles, G.K. Ridgeway, M.E. Totten, B.O. Wynn (2002). Analyses for the Initial Implementation of the Inpatient Rehabilitation Facility Prospective Payment System. MR-1500.

Book chapters

G. Ridgeway and J.M. MacDonald (2010). Methods for Assessing Racially Biased Policing in Race, Ethnicity and Policing: New and Essential Readings (S.K. Rice & M.D. White, eds.), New York University Press.

G. Ridgeway (2003). Strategies and Methods for Prediction in The Handbook of Data Mining (N. Ye, ed.), Lawrence Erlbaum Associates, Mahwah, NJ.

D. Madigan and G. Ridgeway (2003). Bayesian Learning and Inference in The Handbook of Data Mining(https://www.routledge.com/The-Handbook-of-Data-Mining/Ye/p/book/9780805849073) (N. Ye, ed.), Lawrence Erlbaum Associates, Mahwah, NJ.

A. Morral, M. Reti, D. McCaffrey, G. Ridgeway (2001). Phoenix Academy treatment outcomes: Preliminary findings from the adolescent outcomes study. NIDA Research Monograph 182:111-112.

D. Madigan, N. Raghavan, W. DuMouchel, M. Nason, C. Posse, and G. Ridgeway (2001). Likelihood-based Data Squashing: A Modeling Approach to Instance Construction in Instance Selection and Construction for Data Mining (H. Liu & H. Motoda, eds.), Kluwer Academic Publishers.

Commentaries and letters

G. Ridgeway (2020). “Transparency, Statistics, and Justice System Knowledge Is Essential for Science of Risk Assessment,” Harvard Data Science Review 2(1).

G. Ridgeway (2013). “Linking Prediction and Prevention,” Policy Essay, Criminology & Public Policy 12(3):545-550.

G. Ridgeway and P. Heaton (2011). “Save Money - Hire Police,” Commentary, Los Angeles Times, November 22, 2011.

G. Ridgeway and N. Lim (2009). “The Decline of Racial Profiling,” Commentary on cnn.com, July 30, 2009.

G. Ridgeway (2009). “Summary of the RAND Report on NYPD’s Stop, Question, and Frisk,” Testimony presented before the New York City Council Committee on Public Safety and Committee on Civil Rights on April 30, 2009, CT-329.

G. Ridgeway (2008). “Study Focuses on NYPD Racial Profiling.” NPR News & Notes, 8 May 2008.

K.J. Riley and G. Ridgeway (2007). “Police Need to Do a Better Job of Explaining Stop-and-Frisk,” Commentary, New York Daily News, December 6, 2007.

G. Ridgeway (2007). “Laws Are No Substitute to Vigilance,” Special to washingtonpost.com’s Think Tank Town, April 18, 2007.

K.J. Riley and G. Ridgeway (2005). “Racial Profiling Won’t Stop Terror,” Special to washingtonpost.com’s Think Tank Town, October 11, 2006.

G. Ridgeway (2005). “Racial Profiling: Still a Worry,” Letter to the Editor, Washington Post, September 6, 2005, Page A24.

G. Ridgeway (2004). “Commentary: Racial Profiling, Not Always Black and White,” RAND Review 28(2):46.

K.J. Riley and G. Ridgeway (2004). “Measuring racial profiling by police,” Law Enforcement News.

G. Ridgeway and K.J. Riley (2004). “Police-search statistics don’t lie, but statisticians can,” Op-ed, Dallas Morning News, February 22, 2004.

Reports, discussions, and conference papers

G. Ridgeway (2023). Data Analysis of Priests and Brothers Substantiated as Child Sex Abusers Associated with the Illinois Dioceses, Report on Catholic Clergy Child Sex Abuse in Illinois, Office of the Attorney General, State of Illinois. pp. 605-633.

A. Chalfin, J.M. MacDonald, G. Ridgeway, R. Ryley (2022). Crime Prevention Through Intelligence and Information Sharing: An Evaluation of an Information Intervention at the Philadelphia Police Department, Penn Crime and Justice Policy Lab Report.

N. Lim and G. Ridgeway (2015). Progress After Ferguson? Good Ideas Need Good Implementation, Commentary on RAND.org.

G. Ridgeway (2013). The Pitfalls of Prediction, NIJ Journal 271:34-40.

G. Ridgeway and D.F. McCaffrey (2007). Comment on ‘Demystifying Double Robustness: A Comparison of Alternative Strategies for Estimating a Population Mean from Incomplete Data’ by Kang and Schafer, Statistical Science 22(4):540-543.

G. Ridgeway (2007). Review of All of Nonparametric Statistics by Larry Wasserman, Journal of the American Statistical Association 102(477):389-389.

G. Ridgeway (April 15, 2006). Generalized Boosted Models: A guide to the gbm package, R vignette.

G. Ridgeway, D.F. McCaffrey, A.R. Morral (June 26, 2006). Toolkit for Weighting and Analysis of Nonequivalent Groups: A tutorial for the twang package, R vignette.

G. Tita, K.J. Riley, G. Ridgeway, and P.W. Greenwood (2005). Reducing Gun Violence: Operation Ceasefire in Los Angeles, NIJ Research Report NCJ 192378.

D. Madigan and G. Ridgeway (2004). Discussion of “Least Angle Regression”, Annals of Statistics 32(2):465-469.

D. Rusk, K. Lin, D. Swartz, and G. Ridgeway (2001). “Bayesian Updating of Damage Size Probabilities for Aircraft Structural Life-Cycle Management”, Proceedings of the 42nd Structures, Structural Dynamics, and Materials Conference, Non-Deterministic Approaches Forum.

G. Ridgeway (2000). Discussion of “Additive Logistic Regression: a Statistical View of Boosting,” by J. Friedman, T. Hastie, and R. Tibshirani, Annals of Statistics 28(2):393-400.

G. Ridgeway (2000). Looking for Lumps: Boosting and bagging for density estimation, In Proceedings of the International Meeting on Nonlinear Methods and Data Mining (S. Borra & A. Di Ciaccio, eds.), pp. 11-25.

G. Ridgeway (2000). Prediction in the Era of Massive Datasets, Proceedings of Statistical Modelling for Data Mining (P. Giudici, ed.), pp. 109-119.

G. Ridgeway (1999). The state of boosting, Computing Science and Statistics 31:172-181.

G. Ridgeway (1999). Generalization of Boosting Algorithms and Applications of Bayesian Inference for Massive Datasets, Ph.D. dissertation, Dept. of Statistics, Univ. of Washington.

G. Ridgeway, D. Madigan, and T. Richardson (1999). Boosting Methodology for Regression Problems, Proceedings of Artificial Intelligence and Statistics ’99 (D. Heckerman & J. Whittaker, eds.), pp. 152-161.

G. Ridgeway, T. Richardson, and D. Madigan (1999). Discussion of “Bump Hunting in High-Dimensional Data”, Statistics and Computing 9(2):150-152.

J.W. O’Kane, G. Ridgeway, and D. Madigan (1999). Statistical Analysis of Clinical Variables to Predict the Outcome of Surgical Intervention in Patients with Knee Complaints, Technical report.

G. Ridgeway and S. Altschuler (1998). Clustering Finite Discrete Markov Chains, Proceedings of the Section on Physical and Engineering Sciences, pp. 228-229.

G. Ridgeway (1997). Finite discrete Markov process clustering, Technical report MSR-TR-97-24, Microsoft Research, September 1997.

G. Ridgeway (1996). Distributed Open Resources for Understanding Statistics – DORUS, September 1996.

Software development

Presentations

2025

2024

2023

2021

2020

2019

2018

2017

2016

2015

2014

2012

2011

2010

2009

  • “Methods for racial profiling analysis,” October, University of Pennsylvania, Philadelphia, Department of Criminology.
  • “Operación cese al fuego, Los Ángeles,” Crimen organizado, pandillas y tráfico de armas, triángulo de inseguridad, September, CEDAN - Centro de Diálogo y Análisis Sobre América del Norte, Tecnológico de Monterrey, Campus Ciudad de México.

2008

2007

2006

2005

2004

2003

2002

2001

2000

1999

  • “Combining Estimators to Improve Performance: Bundling, Bagging, Boosting, and Bayesian Model Averaging,” (with John Elder) Fifth International Conference on Knowledge Discovery and Data Mining (KDD-99), August, San Diego, California. Tutorial presentation.
  • “The state of boosting,” 31st Symposium on the Interface: Models, Predictions, and Computing (Interface 1999), June, Schaumburg, Illinois. Invited talk for the session on Data Mining.
  • “A Method for Bayesian Inference in Massive Datasets,” Boeing, March, Bellevue, Washington. Invited seminar presentation.
  • “Boosting Methodology for Regression Problems,” Seventh International Workshop on Artificial Intelligence and Statistics (Uncertainty 1999), January, Fort Lauderdale, Florida.

1998

Professional activities

2021-2025 – Editor-in-chief, Journal of Quantitative Criminology (with John MacDonald)

2025-2028 – Committee member, ASA Committee on Law and Justice Statistics

2023-2024 – Chair, ASA Committee on Law and Justice Statistics

2021-2024 – Committee member, Policy Committee, American Society of Criminology

2018-2020 – Associate Editor, Journal of Quantitative Criminology

2016-2018 – Editorial board, Journal of Quantitative Criminology

2019-2020 – Committee member, Nominations Committee, American Society of Criminology

2009-2010 – Committee member, ASA Committee on Law and Justice Statistics

2004-2008 – Associate Editor, Bayesian Analysis

2004-2008 – Action Editor, Journal of Machine Learning Research

2000-2007 – Associate Editor, Journal of Computational and Graphical Statistics

2025

External review committee, Center for Criminal and Sociolegal Studies, University of Toronto

Program committee, ACM Conference on Fairness, Accountability, and Transparency (ACM FAccT), June, Athens, Greece

2023

Social Sciences Area Chair, ACM Conference on Fairness, Accountability, and Transparency (ACM FAccT), June, Chicago

Analyst, Report on Catholic Clergy Child Sex Abuse in Illinois, Office of the Illinois Attorney General (report)

Analyst, Bailey v. City of Philadelphia, Case 2:10-CV-05952-SD (2023-present)

2020

Program committee, ACM-IMS Foundations of Data Science (FODS-2020), October, Seattle, WA

Analyst, Chicago PD Consent Decree, Investigation of the Chicago Police Department, Office of the Illinois Attorney General, Case 1:17-CV-06260 (2020-2023)

Analyst, Investigation of the Minneapolis PD, Minnesota Department of Human Rights, Case 27-CV-23-4177 (2020-2022)

2019

Organizer, Inaugural Ingram Olkin S3 Forum: Gun Violence - The Statistical Issues

Member, External review panel for the Center for Statistics and Applications in Forensic Evidence, National Institute of Standards and Technology

Member, Research Advisory Board, Police Executive Research Forum

2017

Analyst, Baltimore PD Consent Decree, US Department of Justice, Civil Rights Division, Case 1:17-CV-00099-JKB (2017-present)

Analyst, Investigation of the Chicago Police Department, Office of the Illinois Attorney General, Case 1:17-CV-06260 (2017-2019)

2016

Analyst, Investigation of the Chicago Police Department, US Department of Justice, Civil Rights Division (2016-2017)

Analyst, Maricopa County Sheriff Consent Decree, US Department of Justice, Civil Rights Division, Case 2:07-CV-02513-GMS (2016-present)

2011

California Attorney General’s Guns, Gangs, and Organized Crime Working Group

2007

California Department of Justice, Firearms Division Committee on the AFS Redesign

2006

Program committee, 12th International Conference on Knowledge Discovery and Data Mining (KDD-2006), August, Philadelphia.

Vice-chair, 2006 SIAM International Conference on Data Mining (SDM-2006), April. Bethesda, MD.

2005

Program committee, The 22nd International Conference on Machine Learning (ICML-2005), August. Bonn, Germany.

Program committee, 11th International Conference on Knowledge Discovery and Data Mining (KDD-2005), August, Chicago.

Program committee, 2005 SIAM International Conference on Data Mining (SDM-2005), April. Newport Beach, CA.

2004

Program committee, Tenth International Conference on Knowledge Discovery and Data Mining (KDD-2004), August, Seattle.

Program committee, Fourth SIAM International Conference on Data Mining (SDM-2004), April, Kissimmee, FL.

2003

Program committee, 2003 IEEE International Conference on Data Mining (ICDM-2003), November, Melbourne, Florida.

Chair, Analysis panel for the Centers for Disease Control and Prevention on the analysis plan for the Anthrax Vaccine Research Program, October, Atlanta, GA.

Program committee, Ninth International Conference on Knowledge Discovery and Data Mining (KDD-2003), August, Washington DC.

Program committee, Third SIAM International Conference on Data Mining (SDM-2003), May, San Francisco, CA.

2002

Participant, Workshop on the statistical analysis of massive data streams, National Academies of Sciences, Committee on Applied & Theoretical Statistics, December.

Program committee, The 2002 IEEE International Conference on Data Mining (ICDM02), December, Maebashi City, Japan.

Program committee, Eighth International Conference on Knowledge Discovery and Data Mining (KDD-2002), July, Edmonton, Alberta, Canada.

Program committee, Second SIAM International Conference on Data Mining (SDM-2002), April, Arlington, VA.

2001

Panelist, Anthrax Vaccine Research Program, Centers for Disease Control and Prevention (CDC), September, Atlanta, GA.

Program committee, Seventh International Conference on Knowledge Discovery and Data Mining (KDD-2001), August, San Francisco, CA.

Program committee, The Eighteenth International Conference on Machine Learning (ICML-2001), June. Williamstown, Massachusetts.

Organizing and session chair, Session on massive datasets, Interface 2001, June, Costa Mesa, CA.

Member of the Advisory Board for the Handbook of Data Mining

Panelist, National Science Foundation initiative on Information Technology Research (NSF ITR).

Program committee, Eighth Workshop on Artificial Intelligence and Statistics, January, Key West, FL.

2000

Program committee, Sixth International Conference on Knowledge Discovery and Data Mining (KDD-2000), August, Boston, MA.

1999

Session chair, Session on mining temporal data, KDD-1999, August, San Diego, CA.

1997

Mathematical Techniques to Mine Massive Data Sets (M3D), August, Chicago, Illinois. Invited participant.

1996

Second International Conference on Knowledge Discovery and Data Mining (KDD-96), August, Portland, Oregon. Conference participant.

Teaching and student advising

Course notes

  • Criminal Justice Data Analytics (CRIM4002/6002) R4Crim
  • Machine Learning for Social Science (CRIM4012/6012) ML4SocialScience

Ph.D. students

2024 – John Gyourko, Credit Checks and Credit Freezes for Children and Youth in Foster Care: Tracking, Remediating, and Preventing Identity Fraud Victimization (committee member)

2023 – Alex Knorre, Essays on Gun Violence in the United States (committee member)

2023 – David Mitre Becerril, The Effects of Neighborhood Investments on Public Safety (committee member)

2022 – Viet Nguyen, Understanding the trade-offs for less punitive sentencing practices (committee member)

2020 – Ruth Moyer, Changes Within the Urban Environment and Their Effect on Crime and the Criminal Justice System (committee chair)

2020 – Jacob Kaplan, The Effect of Lighting and Building Security on Crime (committee member)

2020 – Yuhao Wu, Empirical Studies of the Effects of Legal Reforms on the Criminal Justice System in China (committee member)

2020 – Li Sian Goh, The Policy Evaluation of Measures to Reduce Police Use of Force (Ph.D. committee member)

2018 – Rebecca Umbach, Etiology and Treatment of Neuropsychological and Cognitive Deficits in Relation to Antisocial Behavior (Ph.D. committee member)

2007 – Brent Fulton, Incorporating Traffic Enforcement Racial Profiling Analyses into Police Department Early Intervention Systems (Ph.D. committee member)

2007 – Arnab Mukherji, Agrarian Households in Semi-Arid Tropics: Evaluating Policy Options (Ph.D. committee member)

2006 – Ben Vollaard, Police Effectiveness: Measurement and Incentives (Ph.D. committee member)

2005 – Matt Dixon, The Costs of Aging Aircraft: Insights from Commercial Aviation (Ph.D. committee member)

2004 – Joshua Weed, Effective Capital Provision Within Government (Ph.D. committee chair)

Courses

Year Course Enrollment Institution
2025 Machine Learning for Social Science 18 University of Pennsylvania
Data Analytics in R 32
2024 Machine Learning for Social Science 29
Data Analytics in R 28
2023 Data Analytics in R 36
2022 Data Analytics in R 30
Criminology in Practice 9
2021 Data Analytics in R 31
Criminology in Practice 13
2020 Criminal Justice 134
Research Methods 13
Mathematical Statistics for Criminology 5
Data Analytics in R 38
Criminology in Practice 15
2019 Data Analytics in R 32
Criminology in Practice 14
2018 Statistics for Social Science 27
Criminal Justice Data Analytics 33
Criminology in Practice 17
2017 Statistics for Social Science 15
Criminal Justice Data Analytics 36
Criminology in Practice 19
2016 Statistics for Social Science 18
Criminal Justice Data Analytics 23
Criminology in Practice 16
Research Methods 20
2015 Criminology in Practice 23
Criminal Justice Data Analytics 32
Criminal Justice Data Analytics 14
2014 Criminology in Practice 12
2011 Applied Statistics 39 UC Irvine
2010 Applied Statistics 25
2009 Empirical Analysis 23 RAND School of Public Policy
Applied Statistics 21 UC Irvine
2008 Empirical Analysis 21 RAND School of Public Policy
Applied Statistics 20 UC Irvine
2007 Empirical Analysis 18 RAND School of Public Policy
Applied Statistics 21 UC Irvine
2006 Modern Prediction and Modeling Methods 19 RAND School of Public Policy
Empirical Analysis 20
Applied Statistics 24 UC Irvine
2005 Applied Statistics 21
2004 Calculus 15 RAND School of Public Policy
Modern Prediction and Modeling Methods 12
2003 Mathematics for Policy Analysis 15
2002 Modern Prediction and Modeling Methods 6
2000 Basic Statistics 150 University of Washington
Statistical Computing 10
1999 Basic Statistics 150
Introduction to Mathematical Statistics 45
1998 Probability and Statistics in Engineering and Science 74