Developing an integrated scobit‐based activity participation and time allocation model to explore influence of childcare on women’s time use behaviour

Focusing on the influence of childcare on women’s time use behaviour, this paper develops an integrated model of activity participation and time allocation, where the former is represented based on a scobit model and the latter based on a multi‐linear utility function under the utility‐maximizing principle. The integration of the scobit model with the time allocation model is done by applying Lee’s transformation. Especially, the scobit model is adopted to relax the assumption, made in the Logit or Probit model, that individuals having indifferent preferences over participation and non‐participation are most sensitive to changes in explanatory variables. Using a large‐scale time use data (66,839 persons) collected in Japan, the effectiveness of the proposed integrated model is empirically confirmed. It is revealed that the probabilities of participating in compulsory‐contracted activities and discretionary activities with the highest sensitivity to changes in explanatory variables are 65 and 81%, respectively. Variances of social childcare variables explain about half of the total variance of the time use for discretionary activities; however, for compulsory‐contracted activities, social childcare variables explain only less than 1% of the total variance of activity participation and less than 10% of total variable of time allocation.