http://www.calculatedriskblog.com/2014/12/the-futures-so-bright.html
Then read this:
http://www.bloomberg.com/news/articles/2015-05-11/a-former-pessimist-on-why-the-bull-market-isn-t-dead-yet
Richard Bernstein, back in 2012, pointed out that inflation concerns were overblown, and the market was "climbing the wall of worry". This update doesn't change much.
Fundamental to a lot of this analysis is underlying demographics. The mid 1970s had smaller birth cohorts than earlier and later years, and the Millenials were bigger birth cohorts at least in some years than their boomer parents. The oldest millenials are reaching their mid-30s, about the latest you can push reproduction and have high confidence that it will be Just Fine without assistance. Assuming you don't believe that Millenials will fail to reproduce themselves (hey, it could happen), at some point, as we move through the decade and a half plus of that "generation", more and more people will be looking around to buy a house in the burbs (close in burbs, but still, not right in the expensive city core, because 2 bedrooms is just too tiny for a family of 4 to be happy in). That will drive residential investment, creating jobs, and creating an economic tide of diapers and plastic crap for the kiddies to play with. Or maybe 3 D printed toys, but whatevs.
The middle birth year of the Millenials, by my calculations is 1989, give or take. And a person born in 1989 will reach 35 in 2024, give or take. If we aren't at an economic peak in or around that year, I will be a Very Surprised Person, or possibly dead from the comet strike that happened a couple years earlier.
This is not investment advice.
ETA: I feel compelled to add. There could be one or more "corrections" between now and then (declines in equity and other markets of 5-10% or more). Also, there are still a lot of nuclear weapons on this planet. Bad, bad shit could happen. I'm just sayin'.