"Since last time we spoke, things have deteriorated dramatically" in the US economy, Ken McCarthy, Cushman & Wakefield's managing director for the New York area, told reporters at the company's quarterly media event held Tuesday. While office-using employment represents 21% of all US jobs, it has accounted for 40% of the layoffs nationwide over the past several months. "This is very much a white-collar recession," McCarthy said.

Locally, that has meant vacancy rate increases well into the double digits. Jones Lang LaSalle puts Manhattan's overall vacancy rate at 10.2% for Q4, up 43% from a year earlier and the highest since 2004. C&W's Q4 report puts the island's office vacancy rate at 8%, but does use the 43% figure to describe the year-over-year increase in available space.

Although the deepening economic crisis centered on the financial services sector, the biggest increase in Manhattan office vacancy has not been Downtown, but in Midtown. There, the class A vacancy rate has reached 9.2%, according to C&W, thus exceeding the equilibrium range of 7% to 9%.