(As a Baby Boomer myself, I'll preface this with the obligatory "Fuck you, get off my lawn, my generation spent our lives paying taxes for our parents' generation's Social Security and more taxes paying for their wars". Now that that's over with, I've got a more serious point to make.)
There's a significant demographic change between the Boomers' Parents' Generation, who generally had 4 kids, and the Boomers and later generations who've mostly had 2 or fewer, which means that the population's getting a lot older on average, and as the boomers retire (which they're starting to), there'll be a lot more retired non-working people than workers, even after the levels of immigration that are politically likely in the US, Japan, and Europe. That doesn't just affect Social Security and Medicare:
- - Pensions, for those of us who had that kind of job, are paid for by some combination of profits invested by the companies we worked for. There's less profit being made by fewer workers.
- - Stocks and bonds owned by retired people (or their pension funds) - fewer workers per investor, so they'll be making less profit on investment capital.
- - Interest on savings - fewer workers paying mortgages or loans per dollar of savings, so interest rates will be lower.
- - other effects like that.
Some of that will be balanced by Boomers not being able to afford to retire, or retiring later. But have no fear, the Democrats say that the Social Security Trust Fund will have plenty of money until 2036, when the middle of the Boomers turn 80, too old to go back to work at Walmart, as long as the government is fiscally responsible from now until then.
Another big problem with medical care is that the Boomer generation had a lot of doctors, who are starting to retire, and at least in the US, medical schools haven't had the capacity to crank out enough graduates to replace them. (Should have been one of Obama's first priorities, since it's a really-long-lead-time change to build up medical school capacities.) And the improving economies in India and China mean that while they are starting to train more doctors, they're also starting to be able to afford to hire them in-country for people who haven't had real medical care before, instead of having them all come here to make money.
So yeah, dude, we're all doomed.