More for less. That is a great economic equation. Restaurants do it all the time, gradually raising prices while giving diners progressively smaller portions of food until the falsetto begins.

In the apartment business, it is working a little differently. Reis has reported that U.S. apartment vacancies have risen for the first time in five years, but rent growth has not subsided, nor will it subside during 2015, according to a 2015 multifamily forecast from Pierce-Eislen. It has prophesized that effective rent growth during 2015 will be 4.5 percent in class A and B+ apartment communities, while rising an even more vigorous 5.1 percent in class B and C apartment complexes.

That is good news for investors in the multifamily sector of the market.

And the news is even better in markets such as Atlanta, Denver, Miami, Portland, San Francisco and Seattle, where rental rates are expected to swell by 7.5 percent to 9 percent. This comes on the heels of ren