The Trans-Pacific Partnership — the big free trade deal the Obama administration is trying to hash out with 11 countries around the Pacific Rim — has skeptics on both sides of the aisle. Perhaps that's why economists and writers like Larry Summers, Brad DeLong, Paul Krugman, Dean Baker, and Ezra Klein have all taken shots at figuring out the TPP's merits. The biggest potential problem with TPP is that past international trade deals have eroded middle-class jobs, particularly in manufacturing, while increasing incomes at the top, thus creating even more of an hourglass economy.