NYC-WTC_000187725

NYC 9/11 Public Portal Document

62 The frequency distribution of the parcel universe indicated that one- and two-family dwellings comprised two thirds of all recent sales, followed by walk-up dwellings for a cumulative 80 percent. Sales of office buildings and apartment structures were least (collectively 3 percent), and stores and vacant land next most frequent. Nearly half of all parcels were in Queens, three in every eight in Brooklyn, and only 3 percent in Manhattan. Thus, to ensure adequate data points along the spectrum, outward from the CBD, it became necessary to draw disproportionately upon parcels in Manhattan, next most frequently upon parcels in the Bronx and Brooklyn, and least upon parcels in Queens relatively speaking. All parcels with office buildings and apartment structures were chosen, as were all vacant land parcels. The former two building classes were least represented in the universe, while the latter class reflected the truest measure of land value. For the remaining residential and commercial classes, a random sample selection was performed by computer. For each of these building classes, the total sample size was predetermined, using the following formula for sampling a large universe when the standard deviation is known:

1.96a\^ E

where k = 1...6, denotes six building classes, and E is signified at 5% error for a 95% confidence interval. Table 3.1 presents the sample of sales parcels by building class and borough.

Table 3.1 Sample Sales Parcels by Building Class and Borough

Study Area Bldg Class Manhattan Bronx Brooklyn Queens Total Vacant Land 416 1,827 3,396 2,655 8,294 1-2 Family 44 606 2,136 2,848 5,634 Walk-Ups 24 167 717 329 1,237 I Apartments 878 483 621 391 2,373 !

Offices 246 53 90 92 481 Stores 41 54 398 137 630 All Classes 1,649 3,190 7,358 6,452 18,649

CITY_21MC100_006662293

NYC-WTC_000187793