CHICAGO—Perhaps the most hopeful recent change to the US office market has been the rise of high-tech firms and the impact they have had on the nation's CBDs. The subject was just one of many tackled at the NAI Global Market Outlook in Chicago on Wednesday. During the morning session, Jay Olshonsky, president of NAI Global, asked panelists Peter Linneman, chief economist of NAI Global, and Sam Zell, chairman of Equity Group Investments whether or not tech firms could produce enough demand to sustain the office market over the long term.

“Tech has been the single biggest tenant in the recovery,” replied Zell. However, he remains reluctant to give a clear-cut endorsement of the sector. “The tech business today is thriving on the availability of capital” and until its companies have solid business plans and products, instead of ideas, it would be naïve to consider it a true asset class.

Zell estimated that WeWork, a New York-based global operator of collaborative workspaces, has taken several million square feet of space in the US, much of it used by tech start-ups. “If there is a tech bust, how fast does that space empty out?”