Calculation of a Population Externality
计算生育行为产生的人口外部性大小，假设温室气体排放是严重问题且政府最优限制排放，发现该外部性在很多假设下都很大。
It is known that when people generate externalities, a birth also generates an externality and efficiency requires a Pigou tax/subsidy on having children. The size of the externality from a birth is important for studying policy. We calculate the size of this “population externality” in a specific case: we consider a maintained hypothesis that greenhouse gas emissions are a serious problem and assume government reacts by optimally restricting emissions. Calculated population externalities are large under many assumptions.