Family changes and public transport use 1984–1987

Abstract

Panel data are used to investigate what happens when people have some important transitions or changes in their life-cycle, employment status, income, or car ownership. Only three years data are available, and the pace of transition is slow: as a result relevant sample sizes are rather small. The analysis is carried out in two stages: results are given from a two year period, and these are used to generate hypotheses checked with data from the third year.

It is found that in many cases the effects on mobility are different from what would be expected from cross-section data. In particular:

• - car ownership changes are substantially less than expected;

• - public transport does not benefit as much as expected when people become members specific dependent or “captive” groups.

These results indicate that the effects of income growth on car ownership and therefore on public transport may not be as drastic as feared. But on the other hand it may be more difficult for public transport to secure a captive base market than hoped. Both results suggest that policy and marketing strategies may be decisive.

The public transport market in two weeks over two years consist of approximately equal proportions of loyal, lost, and new people. There is a slight tendency for the loyal passengers to be those who have not had major transitions in their families, but it is easier to attract new passengers from those who have had such transitions.

Data from the third year gives some indication (but not conclusive proof) that in the longer run there may be some convergence to the cross section relationships. Overall, it begins to look as though dynamic or delayed effects continue to operate over a period of five years or so for public transport use, and over ten years for car ownership.