NYC-WTC_000187725

NYC 9/11 Public Portal Document

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I EEa jln (+ Pi, j,k,in (1) 1 n

Where, li a 2>0 for each J=l, . . ., L, p>0 and P+Ea ^=1.

(1') The Ujj^n.^’s stand for idiosyncratic utilities which vary among households for each residential choice conditional on each employment zone i. The Cjj^^.^'s measure systematic fixed effects for each residential choice 'for workers employed at i. The Wjj^’s stand for the subutility function of exogenous attributes of the |i housing type k and the residential zone j. The >^in;ijkm's are the number of shopping trips per year made to the shopp'ing zone 1 via mode n, by a household employed at i and choosing (j,k,m). The above utility function incorporates two crucial assumptions. First, that the utility derived from shopping in a particular destination is a function of the number of shopping It trips made to that destination. It would be more appropriate to li assume that households do not derive utility from the number of shopping trips per se, but from the quantity of goods and services 11 they purchase on those trips. However, if the demand for the quantity purchased per trip is inelastic, then it is easy to show that the utility derived from shopping at a destination can be i measured by the number of trips made to that destination. Second, the fact that shopping trips to different destinations enter the utility separately (instead of being summed together) implies the treatment of alternative shopping destinations as differentiated "goods". The household’s workplace i is given and remains fixed. Given the workplace, the household evaluates each residential choice (j,k,m), and for each such potential choice decides how many shopping trips it will make to each shopping destination and by each of the available modes if that (j,k,ro) were actually chosen. To make this nested decision, the household must consider maximizing its utility with respect to the annual shopping trip distribution given by the (of which there are LN), given the annual budget constraint'. J We specify the household's budget constraint as follows for each ijkm: (2) 1 n

Here, By^ is the annual generalized income of the single­ worker household employed in zone i, where y^ is monetary income. Generalized income is defined as the sum of monetary income plus

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NYC-WTC_000187761