Data_Sheet_1_Contemporary and dynamic effects of socio-economic factors on physical (in)activity: Does intensity matter?.PDF

ObjectiveThis paper identifies varying contemporary and dynamic effects of socio-economic factors on individuals' decisions to allocate their time to physical activities when the intensity of these activities comes into play.
MethodsBased on repeated cross-sectional data sourced from the Argentinean National Risk Factor Surveys of 2005, 2009, and 2013, we developed 18 fictitious cohorts to set up a pseudo panel. To address endogeneity problems, four econometric specifications were estimated: OLS, Heckman two-stage model, fixed- and random-effects models.
ResultsWe find that changes in the opportunity cost of time are highly significant and provide shifts in individuals' decisions regarding the allocation of their time to physical activity consumption. When considering the intensity at which physical activities are consumed, increased income impacts less, suggesting that individuals faced with a wage increase reduce the time of consumption but increase its intensity. An interesting finding is that employed people consume more physical activity than inactive individuals. This indicates that the substitution effect produced by an increase in the wage rate is less than the income effect. Additionally, the increase in the coefficient of employed persons is greater when the intensity factor is considered, indicating that for employed individuals a trade-off between time and intensity is generated. We also found that higher levels of education increase the probability of participating in physical activities, but decrease the time spent in such activities. Furthermore, there are heterogeneous impacts on physical activity consumption between males and females, which can be observed in the strong effect of household production for women with at least one child. Finally, such impacts remain in a variety of estimated specifications.
ConclusionsThese results may be useful in order to suggest some tools for the design of interventions that are aimed at increasing participation in physical activities.

**研究目标** 本文旨在探讨社会经济因素在体育活动强度维度下，对个体分配时间参与体育活动的决策所产生的差异化即时效应与动态效应。
**研究方法** 本文采用2005年、2009年及2013年阿根廷全国危险因素监测调查的重复横截面数据（repeated cross-sectional data），通过构建18个虚拟队列（fictitious cohorts）搭建伪面板（pseudo panel）数据集。为解决内生性（endogeneity）问题，本文共设定四种计量模型设定进行估计：普通最小二乘法（Ordinary Least Squares, OLS）、赫克曼两阶段模型（Heckman two-stage model）、固定效应模型（fixed-effects models）与随机效应模型（random-effects models）。
**研究结果** 本文发现，时间机会成本（opportunity cost of time）的变化对个体分配时间参与体育活动的决策影响极为显著。当纳入体育活动强度维度时，收入提升的影响相对减弱：面对工资上涨的个体，其参与体育活动的时间会减少，但会提升活动强度。一项有趣的发现是，在职群体比非在职群体参与更多的体育活动，这表明工资上涨带来的替代效应（substitution effect）弱于收入效应（income effect）。进一步而言，当考虑活动强度因素时，在职群体的回归系数增幅更大，说明在职个体在体育活动的时间投入与强度之间存在权衡取舍。此外，受教育程度越高，个体参与体育活动的概率越高，但实际投入的活动时长会缩短。同时，男性与女性在体育活动参与上存在异质性影响（heterogeneous impacts）：对于至少育有一名子女的女性而言，家庭生产（household production）活动的影响尤为显著。最后，上述结论在多种模型设定下均保持稳健。
**研究结论** 本研究结果可为设计提升公众体育活动参与度的干预措施提供理论参考与工具支撑。