Do changed economic conditions discourage you from launching a startup?

Nope. If anything, rough economic times are the best time to start a startup, IMO. My reasons for thinking this are multiple, but among others there's the point that other companies are pulling back / scaling down / exiting markets, or just not launching at all, etc. You can take advantage of this, in theory, although it implies that you have to have a way to run really lean (or somehow manage to find funding, which may not be possible). To me, this is where bootstrapping / self-funding really shines.

As another view, @pg thinks that economic conditions don't matter much, vis-a-vis startups:

http://www.paulgraham.com/badeconomy.html

As those examples suggest, a recession may not be such a bad time to start a startup. I'm not claiming it's a particularly good time either. The truth is more boring: the state of the economy doesn't matter much either way.

If we've learned one thing from funding so many startups, it's that they succeed or fail based on the qualities of the founders. The economy has some effect, certainly, but as a predictor of success it's rounding error compared to the founders.