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Table 7 Simultaneous Poissons Model for Vehicle Fleet Ownership

Table 7
Simultaneous Poissons Model for Vehicle Fleet Ownership

Dependent variable: total vehicles owned and distribution among cars, SUVs, pickups, and vans   Beta SE t-stat P-value
Vehicle price/income   –0.2213 0.0075 –29.40 0.000
Car Constant 0.148 0.021 7.03 0.000
Household size 0.0699 0.0043 16.30 0.000
Population density –0.1519 0.0081 –18.70 0.000
Income per HH member 0.02 0.0042 4.77 0.000
SUV Constant –2.8437 0.0553 –51.40 0.000
Household size 0.273 0.0118 23.10 0.000
Population density –0.4526 0.0311 –14.60 0.000
Income per HH member 0.1899 0.0095 20.00 0.000
Pickup Constant –0.6725 0.0383 –17.60 0.000
Household size 0.0715 0.008 8.92 0.000
Population density –0.9598 0.0281 –34.20 0.000
Income per HH member –0.1102 0.0093 –11.80 0.000
Minivan Constant –3.1526 0.058 –54.30 0.000
Household size 0.4446 0.0103 43.00 0.000
Population density –0.3993 0.0303 –13.20 0.000
Income per HH member 0.0262 0.0141 1.86 0.031

 

Log-likelihood function  
Constant only –89026.8
Convergence –84399.8
Pseudo-R2 0.052

Number of observations: 32,596 households
Model form: Number of vehicles of type i owned ~ Poisson (λi ) with λi = exp(β′iXi) + βprice/income x Price/Income