In Europe and North America, many boomers came of age in a time of increasing affluence and widespread government subsidies in post-war housing and education, and grew up genuinely expecting the world to improve with time. Those with higher standards of living and educational levels were often the most demanding of betterment. In the early twenty-first century, baby boomers in developed countries, with a few exceptions, are the single biggest cohort in their societies due to sub-replacement fertility and population aging.