Get rid of the $100 bill. Heck, maybe get rid of the $50 bill, too. So says Lawrence Summers, a former economic adviser to President Obama and ex-Treasury secretary. Summers points to research showing that corruption is aided by paper currency in larger denominations, such as Uncle Sam’s $100 bill and the 500-euro bill ($557 U.S. equivalent). How so? It’s easier for criminals and terrorists to move lots of cash illicitly in large bills. A million dollars in €500 bills weighs just 2.2 pounds, Summers writes in a blog post on the Washington Post website. The same amount of money...