Régulation et Environnement

Du 25/02/2019 de 12:00 à 13:00

salle R1-13, campus Jourdan - 75014 Paris

GERLAGH Reyer (University of Tilburg)

Family Planning and Climate Change

Historical data show that the increase in emissions is for only one-fourth attributable to the growth of emissions per person, whereas three-fourths are due to the growth of population. This striking evidence notwithstanding, the majority of climate-economic studies focus on emissions through the lens of energy externalities in production and consumption activities, and on policies to correct these. Population dynamics in those models is typically taken to follow exogenous trends. Yet population growth is a key component of projections of future emissions. Population is expected to rise to around 9.8 billion by 2050, and climate economists must include the environmental consequences of individuals' reproductive decisions into their analyses. In this paper, we study the interactions between climate change and population dynamics. We develop an analytical model of endogenous fertility and embed it in a calibrated climate-economy model. The social optimum can be implemented through carbon pricing policies and policies aiming at smaller families. Population without family planning policies peaks at 12 billion, while optimal family planning brings the peak back to 9 billion. If family planning cannot be addressed as a separate policy instrument for climate policies, carbon taxes need to be lowered. Our results present family planning as an integral part of climate policies and quantify the costs of neglecting the interaction.