The easier it is for the factors of production to move to where they are most valuable, the more efficient the allocation of the world’s scarce resources is likely to be and the faster GDP will grow. Apart from continental drift, land is immobile. Capital has long been extremely mobile within countries, and, with the rise of globalization, it is now able to move easily around the world. Enterprise is mobile, although to what extent depends on the particular entrepreneur. Some members of the labor market zoom around the world to work; others will not move to the next town. Capital controls are the main obstacle to capital mobility, and these have been mostly removed or reduced since 1980. The sources of labor immobility are more numerous and complex, including immigration controls, transport costs, language barriers and a reluctance to move away from family or friends. Workers are far more mobile within the United States than they are within the European Union or within individual EU countries. Some economists reckon that the willingness of workers to move to where the work is helps to explain the stronger economic performance and lower unemployment of the United States. Can you sometimes have too much mobility? Certainly, some developing countries have suffered from hot money rushing into and then out of their markets. In general, the possibility that a factor of production may suddenly move elsewhere can create serious economic problems. For instance, an employer may think twice about investing in training an employee if it fears that the employee may suddenly take a job with another firm. Similarly, entrepreneurs are unlikely to take the risk of pursuing a new idea if they fear that their capital may disappear at any moment, hence the importance of having access to long-term capital, such as by issuing bonds and equities.