The Value Gap is a MarketWatch Q&A series with business leaders, academics, policymakers and activists on reducing racial and social inequalities. While slavery in the U.S. was abolished more than 150 years ago, organizations that profited from it still operate today — and it’s in their best interest to fully atone for the past, says Sarah Federman, an expert on the role of businesses in mass atrocities. One financial-services giant based in the U.K. has set a good example for how to make amends, according to Federman, who is a professor of conflict resolution at the University of San Diego’s Kroc School of Peace Studies and the author of “Last Train to Auschwitz: The French National Railways and the Journey to Accountability.” The insurance and reinsurance market Lloyd’s of London researched its historical ties to slavery, made those findings available and offered an unequivocal apology two years ago, she said.