A lack of stability in home prices has made it more difficult for the Obama administration to curb government's role in the country's mortgage-finance giants. David Goldman/AP hide caption

itoggle caption David Goldman/AP

Former Fannie Mae CEO Franklin Raines (right) testifies on Capitol Hill in December 2008. Former Freddie Mac CEO Leland Brendsel (center) and former Fannie Mae chief Daniel Mudd (left) listen. Susan Walsh/AP hide caption

itoggle caption Susan Walsh/AP

Sales of bison meat like this sirloin steak have risen in recent years, as more consumers look for red meat that is lower in fat and cholesterol than most beef. Larry Crowe/AP hide caption

itoggle caption Larry Crowe/AP

A TextMyFood servers' instruction screen shows pending requests sent via text message from customers. Courtesy of TextMyFood hide caption

itoggle caption Courtesy of TextMyFood

Economists agree that the effort to recalculate the tax system should be guided by the principles of efficiency and simplicity. iStockphoto.com hide caption

itoggle caption iStockphoto.com