His interest in prisons began "almost by accident," says the new director of the Kennedy School of Government's Multidisciplinary Program in Inequality and Social Policy. Bruce Western, a sociology professor hired away from Princeton in 2007, once studied organized labor. He recalls a pivotal conversation with a colleague about the way many European states use social-welfare programs to manage disadvantaged populations, while the United States, whether by design or accident, has used prisons for the same purpose. That exchange grew into a vocation: Western is now author or coauthor of more than a dozen articles on the causes and consequences of incarceration, has written one book and edited two others on the topic, and has testified before Congress on options for reforming the criminal code and prison policy. Although his work challenges the notion that higher incarceration rates have caused a major decrease in crime, he says it has not stirred much controversy; the desperate need to deal with surging prison costs and recidivism seems, he says, to keep people off political and moral soapboxes. Western -- who hails from Australia and lives in Brookline with his wife and three daughters -- taught a course on the sociology of crime and punishment for inmates at a maximum-security prison in New Jersey and says he'd like to do something similar here, perhaps joining student volunteers who teach classes at the Suffolk County jail. Because most jurisdictions have chosen to cut prisoner-reentry programs as prison costs have grown, "An elite university like Harvard," Western says, "really has a role to play."