The baby boomer generation begins with those born at the end of World War II in 1945. The last of the boomer generation is a matter of opinion, but let's call it 20 years later, for those born in 1965. This generation reaches the traditional retirement age of 65 in 2010 to 2030. At that time they (OK, we) will depend on the smaller, younger generations to pay our social security, plus whatever savings we have accumulated while working. So one can envision a difficult period with a lot of older people needing support and not many of working age to do the supporting. From a stock market perspective, it doesn't look good for economic growth.
But lately it has occurred to me that this timetable actually happens earlier. Income starts declining around age 55, due to early retirement, age discrimination, or out-of-date skills and perhaps declining energy. At the other end of things, by 2020 the boomer generation will be reduced in size and importance. So the bad period may actually be 2000-2020.
The image I have is of boomers having had their peak earning years in the 1990s, working and saving hard for retirement. This period is now fading and may at least partially explain the three year bear market. And foreshadow 17 more bad years - yikes!