Transmission of Flood Damage to the Real Economy and Financial Intermediation: Simulation Analysis using a DSGE Model

July 29, 2022

By Ryuichiro Hashimoto and Nao Sudo

This paper quantitatively assesses the indirect effect of floods on the real economy and financial intermediation in Japan by estimating a dynamic stochastic general equilibrium (DSGE) model that incorporates a mechanism through which floods cause the capital stock and the public infrastructure to depreciate exogenously, using the data on flood damage recorded in the Flood Statistics released by the Japanese government. The result of the analysis is twofold. First, flood shocks dampen GDP from the supply side by reducing the capital stock inputs. The decline in GDP then impairs the balance sheets of firms and financial intermediaries, resulting in disruptions to financial intermediation and thus dampening GDP further from the demand side. Even when the direct damage due to floods is fully covered by insurance, the downward pressure on GDP endogenously deteriorates the balance sheets of these sectors, causing the same mechanism to operate. Second, the quantitative impacts of flood shocks on GDP up to now have been minor compared to the standard structural shocks that are considered important in existing macroeconomic studies, including shocks to total factor productivity (TFP) and the subjective discount factor. According to the estimates that use the relationship between the key variables in our model together with climate change scenarios published by an external organization, the impacts of these shocks could become somewhat larger in the future.

Given that we are recovering from flooding in St. Louis, this hit a nerve. Of course, if you destroy some capital, the economy suffers. But there is this persistent myth that a natural disaster is good because it provides jobs for the recovery. I wonder whether this class of models could say something in this regard when there is under-employment or when a geographically limited area is hit (leading to reallocations).

Fertility and migration

July 14, 2022

By Arianna Garofalo

Over the past three decades, the drop in fertility rates has been accompanied by high rates of migration in several developing countries. We argue that migration affects fertility negatively in the countries of origin. To analyze the effect of migration we build a fertility choice model, based on De La Croix (2014), with endogenous migration decisions. In this framework, when a member of the household migrates abroad, income increases due to remittances but at the same time, individuals left at home face a much higher opportunity cost time. This means that household members have less time to devote to taking care of the children and the consequence is a decrease in fertility. We calibrate the model to match the migration rates and to quantify the effect of migration on the fertility rate in those countries. To this end, we first show that the model can replicate the high rate of migrations in several developing countries. Then we perform two counterfactual exercises to address the effect of our mechanism. In the first exercise, we keep the migration constant as in the benchmark model while we give a higher value to the time cost of migration. The result is an increase in fertility. In the second exercise, we quantify how the differences in the time cost of migration affect the differences in fertility. We found that the time cost of migration accounts for 53% of the fall in the fertility of the developing countries in our sample between 1990 and 2017.

Open migration is the solution to several global problems. This paper shows that it can also contribute is important ways to reducing population growth, at least if the children members remain in the origin country and thus rely on remittances.