The development of agriculture led to increased trade as agricultural areas traded surplus crops for other goods. Government officials regulated trade and exchange rates—over time, government's role would expand with trade. Agriculture also led to an increase in cities; this also necessitated more governance. had already settled in an area rich with hunting and gathering resources, where they began to establish private property rights. When wild plants or animals became less plentiful, they argue, people chose to begin farming instead of moving on. Agriculture was not an improvement over hunting and gathering due to the extra leisure time, greater health benefits, and lack of poverty that was offered by hunter-gatherer societies. Jared Diamond, a professor of geology at UCLA, describes how some groups of hunter-gatherers, such as the Bushmen spend only “12-19 hours obtaining food,” and the Hadza nomads of Tanzania spend “14 hours or less.” Since hunter-gatherers did not have to work as hard nor spend as much time collecting food, this allowed for extra free time to do whatever they pleased. Furthermore, according to Canadian anthropologist, Richard Lee, there was a “rhythm of steady work and steady leisure... throughout the year” in the gathering portion of the community. This allows for an important schedule between the two pastimes to be cemented into society, which decreases stress in the community and leads to a better quality of life. Also, Lee states that “a woman gathers on one day enough food to feed her family for three days” so that the community doesn’t solely have to rely on the unpredictability of hunting. Because they had more leisure time, this allowed the hunter-gatherer societies to “sleep a good deal,” which also benefited their health. Hunter gatherers had better health than agriculturalists due to their more nutritional diets and the fact that they were less prone to certain diseases. Nathan Cohen, an American anthropologist and author of Health and the Rise of Civilization, says, “There is evidence that primitive populations suffer relatively low rates of many disease [and enjoy several nutritional advantages] compared to the more affluent modern societies.”