National, state, and local policy makers have increasingly focused their attention on policies toward economic growth, especially efforts to raise the rate of investment. Recent studies of economic growth have raised a debate over the role played by the investment rate in the long-run...

Researchers, commentators, and politicians have devoted steadily more attention to infrastructure in response to claims that inadequate accumulation of public capital has contributed to substandard U.S. economic growth. Despite this, the link between infrastructure and productivity growth...

Over the past decade, concern over potential global warming has focused attention on the emission of greenhouse gases into the atmosphere, and there is an active debate concerning the desirability of reducing emissions. At the heart of this debate is the future path of both greenhouse gas...