By analyzing the macro-economic situation and current research,the authors argue that nationwide labor shortage at present time is the consequence of the "vote with feet" due to the lower actual wage than the reserve wage.It is different to use the unitary model of New Family Economics to analyze the logic reaction of rural migrant labors in facing the social reality from that using the individual economics behavior approach.Rural household invests in its member’s labor capital in order to maximize the household utility and avoid risk in the context without sufficient financing capital and educated human capital.In conclusion,this kind of logic reaction leads to the ineffective releasing of "demographic dividend" in modern manufacture industry and agriculture,and the labor shortage and industrial agriculture which is negative environmental externality.