Citi Habitats, the city's largest rental brokerage, has released rental market reports for years, but never gave statistics about transaction volume. After the release of Miller's much-hyped first rental report, however, Citi Habitats in late September released a report saying it had done more than 5,700 transactions between May and August of 2009. Then, when it released its third-quarter report, it included data for the first time about the number of transactions, saying the company had done more than 3,800 rentals in the third quarter, approximately 500 more than in the same quarter of 2008.

Gary Malin, the president of Citi Habitats, said he has "always wanted to" release transaction information, and that the decision was not a direct reaction to Miller's report.

In explaining discrepancies in the data, Miller said Citi Habitats, which uses only its own transactions data for market reports, said the firm is likely using different measurement parameters than he is.