We dropped on you this morning the gong-rattling pronouncement that Manhattan is now a tenant's market by the two most important measures: rents (they're dropping across the board) and vacancies (they're up and climbing).
But there's more to the math.
According to The Real Estate Group New York, which released its November report just before sun-up (PDF here), the number of Manhattan apartment vacancies may be higher than signified. Why? Because some owners of higher-end rentals don't want everyone to know about all their vacancies: "[V]acancies, may actually be even higher than reported, particularly in doorman buildings, as many landlords are not releasing their full vacancy list."
Why would some landlords play their vacancies so close to the chest? More empty apartments might further drive down rents and demand of landlords ever more concessions and incentives to lure tenants.