Charles Mann—president of Charles R Mann Associates in Washington, DC; ASA Fellow; and longtime IMS member—passed away on February 14, 2022, after a long illness. 

In 1996, Charles was elected a fellow of ASA, “for excellence in the application of statistical methodology in the legal and regulatory communities; and for leadership in developing awareness and consideration of professional ethics in the practice of statistics.” He had served on the ASA’s ethics committee for over a decade and was instrumental in developing a permanent ethics code for the association

Charles, who was born March 27, 1941, held a BS in applied mathematics from Brooklyn’s Polytechnic Institute, an MS in mathematical statistics from Michigan State, and a PhD in statistics from the University of Missouri. He was an instructor at the University of Maine, Orono, and an assistant professor in the department of statistics at The George Washington University. Before he opened his own firm, he headed and became a vice president of the statistical services division of Group Operations, Inc., in Washington, DC. He authored the entry on underutilization in the Encyclopedia of Statistical Sciences.

In 1977, Charles became founder and president of Charles R Mann Associates and was one of the pioneers in the provision of statistical services to legal practitioners in employment law. He participated in more than 100 seminars, workshops, and individual presentations to lawyers on various statistical applications and methodologies to be applied for proper statistical evaluation of employment discrimination claims. He also helped educate the legal profession to use multiple regression analysis to evaluate equal pay claims, and to use only statistically significant differences in application and/ or employment rates for establishing a prima facie case. In addition to providing lawyers with advice and reports on statistical analyses, Charles provided expert witness testimony in more than 160 cases, including major and landmark cases in a variety of legal arenas, and participated personally in settlement negotiations for several major national class action cases. 

The Equal Employment Opportunity Act of 1972 first authorized the EEOC and private individuals to bring lawsuits under Title VII, which prohibits employment discrimination on the basis of race, sex, and national origin. In 1973, a nationwide class action lawsuit—O’Bannon and EEOC v. Merrill Lynch, Pierce, Fenner & Smith, Inc.—alleged Merrill Lynch discriminated against women applicants for a stockbroker position while the EEOC alleged discrimination based on race, sex, and national origin in all positions. Charles helped forge a defense for the Merrill Lynch lawyers, which resulted in an affirmative action consent decree that adopted Charles’s unique statistical methodology for establishing goals and timetables for hiring minorities and women. This ‘five-year plan’ compares the percentage of minorities and women actually employed with the percentage in the ‘comparable’ workforce and then establishes goals and timetables when a statistically significant difference exists in the employment rate. This was a landmark settlement and set the standard for the brokerage industry.

Many early employment law cases were litigated by parties looking only at the number and percentages of minorities and women actually employed, versus their corresponding number and percentages in the civilian labor force. This was commonly referred to as the “any difference rule.” For example, where a company had no women employed out of five electrical engineers compared to 20 percent of women in the labor force, a prima facie case of discrimination was established under the “any difference” rule. Charles was tireless in his attack on such uncritical thinking and incorrect methodology. He urged lawyers for both plaintiffs and defendants to focus on the “expected” numbers: to use statistics in a more refined way to ascertain whether the null hypothesis of nondiscrimination should be rejected. 

Parallel with this work in employment discrimination litigation, Charles provided expertise in the original development of affirmative action programs for federal contractors and subcontractors. This longstanding Department of Labor program was established by Executive Order 11246 and administered by the Office of Federal Contract Compliance Programs (OFCCP). Among other regulations, the order requires government contractors and subcontractors to “… take affirmative action to [ensure] that applicants are employed, and that employee[s] are treated during employment, without regard to their race, color, religion, sex, or national origin.” As enforcement increased, the secretary of labor approved an interpretation that authorized a rule requiring contractors to seek to achieve and maintain a percentage of women and minority workers exactly equal to their estimated availability in the external civilian workforce. Charles was first to recognize this as another version of the “any difference” rule in litigation and vigorously opposed it, waging nearly a one ‘Mann’ war with the OFCCP to recognize statistical procedures to measure more accurately whether the differences were statistically significant. 

The OFCCP then abandoned the “any difference” rule and adopted the 80 percent rule, which Charles likewise fought. That is, the percentage of minorities and women in the internal workforce had to be at least 80 percent of their corresponding availability in the external workforce. As Charles successfully educated the legal profession in using proper statistical analyses, it became clear there needed to be a sound statistical basis for taking affirmative action in setting goals and timetables for the employer to avoid direct violations of Title VII. This dispute led to the seminal case that vindicated Charles’s views and can be seen as the crowning achievement in his career of advising the courts and legal profession in statistics in the employment context. Firestone Synthetic Rubber & Latex Co. & Koppers Company, Inc. v F. Ray Marsha, et al., 507 F. Supp. 1330 (E.D. Tex. 1981) was a declaratory judgment action brought to prevent the debarment of a contractor for, among other things, only declaring underutilization of minorities and women when their internal employment rate was statistically significantly less than their availability in the corresponding labor force (at the .05 level). Enforcement of the “any difference” rule was finally ended. 

In addition, Charles’s use of regression to analyze pay data was the first to be accepted by the Supreme Court in Bazemore v. Friday. That decision established the criteria courts now use to evaluate the reliability of regression analyses submitted in litigation and to justify affirmative action plans. 

Charles was a highly esteemed mathematical statistician, responsible for the court’s understanding and adopting statistical analyses and methodologies still recognized and used in a wide variety of cases today, benefiting lives by helping to establish rigorous and transparent statistical methods for accountability in the legal system.

Written by Lee-Ann C. Hayek, Chief Mathematical Statistician and Senior Research Scientist, Smithsonian Institution, Washington DC