My post “12 facts about guns and mass shootings” included a mention of Israel and Switzerland, societies where guns are reputed to be widely available, but where gun violence is rare. Janet Rosenbaum, an assistant professor of epidemiology at the School of Public Health at the State University of New York (SUNY) Downstate Medical Center School, has actually researched this question, and she wrote to tell me I had it wrong. We spoke shortly thereafter on the phone. A lightly edited transcript of our conversation follows. Ricky Carioti — The Washington Post Ezra Klein: Israel and Switzerland are often mentioned...