The demographic trends discussed in earlier chapters makes the productivity imperative even more critical over the next fifty years. The rapid global GDP growth of the previous half century, about 3.6 percent annually on average, was driven by growth in both the world’s labor force and in its productivity. For instance, an analysis of twenty countries, including the G19 and Nigeria, shows that there are 2.3 times more employed workers today compared to fifty years ago and that each worker generates 2.4 times more in output than he or she did fifty years ago. Today, however, the demographic trends fueling growth are weakening and even reversing in some countries. The rate of global employment growth could drop to just 0.3 percent annually thanks to declining fertility rates and aging populations, and the world is likely to hit peak employment at some point in the coming half century.