A few months ago somebody posted some links to the smartest parking program I've ever heard about. The prices of parking at the meters changed depending on how valuable the parking spaces were considered. The prices ensured that there were always about 15% of the spaces available. The cities that try it like it.

As far as population goes, within one-hundred years the population of the Earth would be permanently sustainable if there were just a one child per family rule implemented.

Genetics is an unpredictable thing. Having different types of people with different genetics (and intelligence levels) all mixing together is what makes the human population so resistant to diseases. A homogeneous population would be more susceptible to diseases. One bad strain of flu could kill the entire population if we were all related.

Super geniuses didn't only come from super geniuses. Nobody knows which combination of genes will produce such people. Once everybody on the planet has a good job they won't need to produce eight children to help them in their old age.

ChrimsonEclipse you were probably joking about that "(you must be this smart to breed)" comment. It's a funny idea but it would not solve anything. There are smart people doing stupid things all the time.