"Human capital-based theories of cities suggest that large, economically diverse urban agglomerations increase worker productivity by increasing the rate at which individuals acquire skills. One largely unexplored implication of this theory is that workers in big cities should see faster growth...

"One basic problem in business-cycle studies is how to deal with nonstationary time series. The market economy is an evolutionary system. Economic time series therefore contain stochastic components that are necessarily time dependent. Traditional methods of business cycle analysis, such as the...