Several years ago, he said, commercial rents in the area went from $12 to $25 a square foot.

Commercial rents also are lower than in most parts of Manhattan.

Commercial rents are falling for the first time in a decade.

"And having too much 'outside' income like commercial rent is inconsistent with that view."

He would have the city exempt 28,000 small businesses from the tax on commercial rents.

Commercial rents - for a mere 25,000 square feet of store space - stand at $1.6 million a year.

As a result, commercial rents are increasing, according to real estate executives.

In the last few years, the area's residential prices and commercial rents have soared.

While commercial rents in downtown Chicago are high now, there is no guarantee demand will continue.

He added that the neighborhood changes had also prompted rises in commercial rents.