the value of a pace,” or competitor, shaves twenty to thirty seconds off the time of a mile. To rigorously test the value of human proximity, he got forty children to compete at spinning fishing reels to pull a cable. In all cases, the kids were supposed to go as fast as they could, but most of them, especially the slower ones, were much quicker when they were paired with another child. Modern statistical evidence finds that young professionals today work longer hours if they live in a metropolitan area with plenty of competitors in their own occupational niche.Supermarket checkouts provide a particularly striking example of the power of proximity. As anyone who has been to a grocery store knows, checkout clerks differ wildly in their speed and competence. In one major chain, clerks with differing abilities are more or less randomly shuffled across shifts, which enabled two economists to look at the impact of productive peers. It turns out that the productivity of average clerks rises substantially when there is a star clerk working on their shift, and those same average clerks get worse when their shift is filled with below-average clerks.Statistical evidence also suggests that electronic interactions and face-to-face interactions support one another; in the language of economics, they’re complements rather than substitutes. Telephone calls are disproportionately made among people who are geographically close, presumably because face-to-face relationships increase the demand for talking over the phone. And when countries become more urban, they engage in more electronic communications.



