America is sabotaging itself in the global battle for talent

In fact they are extra-useful, since their skills tend to complement those of locals. They bring different experiences, knowledge and contacts, making local co-workers more productive. A Harvard study tried to measure this by looking at what happened to researchers when a colleague died. The loss of an immigrant brainbox reduced co-workers’ productivity (measured in patents) by nearly twice as much as the loss of a native. From this, the study estimated that immigrants in America, though only 14% of the population, are responsible for a colossal 36% of innovation. As the globalisation of capital stagnates, the flow of brains across borders becomes an ever-more important way for new ideas to spread.