Scientist discovers hyperspace with a twist

I believe the setting is an Earth that desperately needs transportation to the stars (overpopulation?)

A scientist discovers hyperspace (I believe he solves a theory that explains how to reach it, but I am not certain). However, he can't get any government agency to believe him and fund his research. Furthermore, government agencies are funding wacky other FTL drives with little chance of success.

Finally, one government representative agrees to see the scientist. The government representative explains that hyperspace was already solved, but that speeds in hyperspace were slower, not faster than those in normal space.

I read this more than 10 years ago and probably more like 20. It was a short story, probably in an anthology book.