The determinants of regional variations in private car ownership: Some evidence from irish data

Abstract

Linear and nonlinear models of per capita car ownership rates are fitted to three cross-sectlons of data for the counties of the Republic of Ireland. The explanatory variables are per capita average real income and population density. The results suggest that both are significant with positive and negative effects respectively. The findings are compared with those from earlier studies of British and American data.

The determinants of regional variations in private car ownership: Some evidence from Irish data: Comment

“…Sanghi found population density alone explaining 64 percent of the variance in the ownership rate, but found income quite insignificant in explaining additional variance. However, it is erroneous to conclude that Sanghi's [5] results are inconsistent with those of Buxton and Rhys [2], McCarthy [3], and Sleeman [5]. This is true because elasticities and R2s tell us different things.…”

“…This point can be best illustrated by taking the estimated function by Sanghi I [6] and calculating income elasticity and population of density elasticity at their mean values. This will put the results of Sanghi [5] and others [2,3,7] on a comparable basis.…”

“…McCarthy [3] finds that Sanghi's [5] results are inconsistent with the results of McCarthy [3], Sleeman [7], Buxton and Rhys [2], and Bennett [i]. He seemed to have based his conclusion by noting that ownership/income elasticities were much higher than ownership/population elasticities in [2,3,7].…”

“…He seemed to have based his conclusion by noting that ownership/income elasticities were much higher than ownership/population elasticities in [2,3,7]. Sanghi found population density alone explaining 64 percent of the variance in the ownership rate, but found income quite insignificant in explaining additional variance.…”

“…This is true because elasticities and R2s tell us different things. McCarthy should have either compared [2,3,5,7] on the basis of R2s and partial R2s or on the basis of elasticities. This point can be best illustrated by taking the estimated function by Sanghi I [6] and calculating income elasticity and population of density elasticity at their mean values.…”