Next month, dozens of world leaders will gather to talk about the global recession at the G-20 economic summit. The last few times they’ve gotten together, it was in London and Washington. This time, the location is Pittsburgh. All jokes aside, the White House says it chose Pittsburgh as a city that weathered an economic collapse, and has become a place with a good deal of optimism. Guest host David Greene talks to the mayor of Pittsburgh, Luke Ravenstahl, as the city prepares to welcome leaders from around the world.