Encouraging procreation isn't a sustainable solution. The planet is over populated and building economic models which depend on an ever growing population (or even one sustained at it's current level) is asking for trouble.
It's true that building an economic model that builds on a growing population is a bad idea. And it it's arguable that building one based on a population that stays the same size is bad, too.
That doesn't change the fact that Sweden has many such programs, and it's the fifth most rapidly shrinking nation. A shrinking population makes any social program where a bulk of the money is spent on the elderly i.e. health insurance or social security is going to take a severe economic hit. The Swedes think that by offering incentives like this one, they can help preserve some of their other programs.
So the state arguably needs to encourage procreation in order to stave off the Japanese style demographic crisis: http://www.foreignaffairs.com/articles/53050/milton-ezrati/j...