Start-ups in different industry groups are classified according to their average complexity. We find that thick regional input markets are conducive to start-up activity in general and complex start-ups in particular, but that some inputs are more important than others.

A growing body of empirical evidence shows that there exists a long-run positive trade-off between inflation and real macroeconomic activity. Within a New Keynesian framework, we examine how increasing returns generate a positive long-run relation between inflation and output.

We question the claim that the largest US cities are Pareto distributed. We show that results of multiple tests on real data are similar to those obtained when the true distribution is lognormal, and largely depend on sample sizes.