Application of a Threshold Regression Model to Household Purchases of Automobiles
The threshold regression assumes that value of dependent variable remains fixed until the concerted action of independent variables and error term induces it to overcome its reaction threshold. The existence of reaction thresholds in purchasing of private cars has been discussed and analyzed. Among main explanatory variables used in micro-economic studies, most significant appear to be household composition, age and education of head, number of earners, number and age of cars, value of stock of cars previously held, liquid assets, net worth, debts and place of residence. The independent variables finally retained in present study are permanent income, education of head household and number of children. To summarize, income appears to be most important variable affecting car purchases by households. There are no doubt other social and demographic characteristics of households which bear on this phenomenon, but nature of these variables as well as mechanisms through which they operate have not been sufficiently investigated and are not yet sufficiently well known to permit us to detect their effect very clearly, in statistical investigations.