The non-partisan Migration Policy Institute says the government spent $18 billion on immigration in fiscal 2012. That’s more than the combined budgets of the FBI; the Bureau of Alcohol, Tobacco, Firearms and Explosives; the Drug Enforcement Administration and the Secret Service. So where is all that money going? And is it paying off? For the answers, we turn to Muzaffar Chishti, the director of the Institute’s New York office and an author of a new report.