We will conduct research along several different fronts to understand the mechanisms of upward mobility. Our research over the last two years has generated a number of important facts, especially on the variation in upward mobility across the United States. This project will develop three different areas to understand why and how such upward mobility occurs. First, we will study the role of college attendance in intergenerational mobility. Second, we will study the place-based differences in take-up of Social Security Disability Insurance. Disability, especially at young ages (i.e., below 35 years old), is disproportionately taken up by children from poor backgrounds, and once on the program these individuals are unlikely to have full productive careers of any kind. Third, we will study the intergenerational pathways that cause children from different backgrounds to become inventors and generate patents, thereby contributing directly to the broad growth in productivity in the United States.