A new federal budget modeling tool developed through the Penn Wharton Public Policy Initiative is being unveiled for public use today. Already it is producing new thinking around two areas very high on the public agenda: Social Security’s funding shortfall, and the economic costs and benefits surrounding immigration. In this interview with Knowledge at Wharton, Kent Smetters, Wharton professor of business economics and public policy, explains how none of the common fixes suggested for the Social Security shortfall will close the gap by themselves, according to the new simulator, and that the impact on the economy from providing a path to citizenship for undocumented workers is basically an economic wash for the U.S. The Penn Wharton Budget Model is a nonpartisan, online, interactive budget-modeling tool available at no cost to users. A demonstration of how the model works appears at the end of the video, or here for Social Security and here for immigration .…