How does government regulation influence the structure of industries? In the coal mining industry, increased safety can be provided with personal protection devices or with engineering controls; but the type of safety standard imposed is important because larger producers have a comparative...

This paper develops a gravity model of immigration. Tests of the model using panel data for 16 OECD countries for 1991-2000 confirm the model's high explanatory power, and examples illustrate its usefulness for testing other hypothesized determinants of immigration.

In one of the most original papers published in <i>Challenge,</i> Hendrik Van den Berg and Matthew Van den Berg try to determine whether markets are really complete enough to make the invisible hand a relevant concept. They attempt to calculate what proportion of our transactions does qualify. Some...

The invisible hand metaphor dates to the 18th century but only gained prominence after neoclassical analysis came to dominate economic thinking late 19th century. Neoclassical economists rigorously established the assumptions necessary for an economy to operate in accordance with the metaphor,...