Linear, non-linear, bi-directional? Testing the nature of the relationship between mobility and satisfaction with life

Travel is one of the most important facilitators of life and has been widely acknowledged as a prerequisite for economic and social activity. Research developing in recent decades has found that limitations to mobility and accessibility can reduce satisfaction with life. To date, research in this field assumes a linear and one-way relationship between the two—i.e. that ‘more mobility’ results in ‘more life satisfaction’. Yet diminishing marginal returns on happiness are found in many related fields such as economics, and there is always the possibility that happier people travel more than unhappy people. To the authors’ knowledge, this paper presents the first attempt to look for evidence of a non-linear relationship between mobility (measured as trip-making) and life satisfaction, and the first to test the direction of causality between the two factors. It uses a sample of some 1500 adults in the Netherlands Mobility Panel. Linear and segmented regression models were used to associate trip-making with satisfaction with life, when controlling for income, age, self-rated health and other demographics. Counter to expectations, five different model specifications suggest that the relationship between trip-making and satisfaction with life is linear. Furthermore, a structural equation model found that the relationship between mobility and satisfaction could run in either direction. This study questions many of the assumptions made about the relationship between transport and subjective well-being. Given the increasing prominence of this topic, much research is needed to further explore these complex relationships.