High-Speed Rail Enables Chinese to Avoid Unhealthy Environs
The social costs of climate change and local pollution depend crucially on the extent to which humans can adapt to extreme environmental conditions. Individuals can adapt in various ways to short-lived adverse environmental conditions, such as elevated air pollution levels. Some may remain indoors or avoid strenuous activities. Others may leave town when pollution is especially bad.
Over the past 15 years, China has built the largest high-speed rail network in the world, with tracks stretching twice the length of the networks in all other countries combined. Between 2010 and 2019, the annual number of passenger trips via the network rose from 290 million to 2.3 billion. One contributory factor has been “haze-avoidance tourism” — the use of short-term intercity travel to avoid extremes in pollution and temperature.
Access to high-speed rail allows travelers to reduce their exposure to air pollution by 7 percent and to extreme temperatures by 10 percent.
In Improved Transportation Networks Facilitate Adaptation to Pollution and Temperature Extremes (NBER Working Paper 30462), Panle Jia Barwick, Dave Donaldson, Shanjun Li, Yatang Lin, and Deyu Rao estimate the extent to which improved transportation infrastructure has reduced exposure to adverse environmental conditions. They draw on in-person credit and debit card transactions from UnionPay, China’s only interbank payment network, to trace travel flows between pairs of cities on a daily basis. They match these data to localized meteorological and atmospheric records.
The researchers find that during periods of extreme environmental conditions, travelers from cities tied into the high-speed rail network are more likely to go to more hospitable destinations than those from cities without network access. The gap widens as hometown conditions deteriorate. Across all environmental conditions in the home city, access to high-speed rail reduces travelers’ average exposure to air pollution by 7 percent and to extreme temperatures by 10 percent.
Shifts in longer-term travel patterns, such as for vacations, account for 71 percent of reduced exposure to extreme pollution and 83 percent of reduced exposure to extreme temperatures. The remainder arises from day-to-day avoidance of unexpected environmental extremes. Passengers traveling relatively longer distances on high-speed rail account for 43 percent of reduced exposure to extreme pollution and 50 percent of reduced exposure to extreme temperatures in the dataset. The remaining effects are due to the greater access that high-speed rail provides to a wider choice of destinations with better environmental conditions, holding distance constant.
By reducing their exposure to adverse environmental conditions, Chinese city-dwellers are living longer and healthier lives. Based on the value of a statistical life for a Chinese traveler, the reduced exposure to air pollution made possible by increased access to high-speed rail translated into nationwide life expectancy gains worth about $2.2 billion in 2015, along with aggregate health savings of about $5 billion per year.
— Steve Maas
