Vehicle Ownership and use Forecasting in Low Income Countries
This study is a macro-level analysis of trends in road vehicle ownership and use in low income countries (i.e. those with GNP percapita of less than$ 3,000 in 1986). Initially a suitable data base is developed from pubtished sources and set against the background of previous work in the area. There is the analysis of the main determinants of car ownership and use followed by medium term forcasts of ownership and use trends in selected countries.
The data base covers tie periodfrm 1966 to 1987 and relases to all countries within the given income bands save for both those where insufficient data exists and small island states. The countries are categorised into five maingroupings according to income levels and base car ownership levels. A different ultimate saturation level of car ownership is taken for each category.
The analysis of car ownership patternsis based upon well established log-linear andquasi-logistic modefling tmhniques to encompass non-linearities in the key relationship between vehicle ownership and income levels. Incorporated in the models are parameters reflecting time trends,Ieves of urbanisation and labour force participation levels in addition to per capita income. Further,comtry specific dummy variables are deployed to capture nation specific effects. While a variety of variables was explored in terms of explaning levels of car usage, a time trend,GDP and fuel prices providedtie most statistically significant set.
Similar exercises relating to commmercial vehicles highlight the significance of a log-linear relationship between vehicle ownership and GDP and a time trend. Different coefficients, however, are appropriate for countries respectively in Sub- Saharan Africa, Asia and Latin America. Commercial vehicle use is seen to be principally influenced by GDP, the price of disel fuel and the availability of road infrastructure.