 My research is about the changing geography of jobs. Many people are aware that employment has polarized, meaning that we have growth of high-end professional technical and managerial jobs and growth of many in-person services, food service, cleaning, security, and a kind of a collapse of the middle of clerical, office, and also manufacturing jobs. And that's been going on for some decades. My work shows how that has actually been driven by a decline in the middle within cities. And it used to be that in urban areas, non-college workers did much more specialized work. They did office work, they did production work. And over the last three decades, that difference has kind of eroded almost completely such that the geography of work for non-college workers is now uniform across places. They are no longer doing more skilled and more specialized work in cities and as that erosion has occurred, the wage premium for less educated workers has also substantially fallen off.