FOR decades China's coal mines served as tragic showcases of greed, corruption and contempt for life: thousands died in accidents every year and many more after prolonged agony from dust-clogged lungs.
Then a striking turn around began. Chinese coal mines became far safer even as they more than doubled output to fuel the country's economic boom—they produced 3.9 billion tonnes in 2014, about half the world total. Last year 931 miners were killed in coal-mine accidents. It was the 12th year in a row in which the death toll reportedly fell.
By one measure of mining safety—deaths per million tonnes of coal produced—China's record had improved twenty-fold since 2002, to 0.24 (see chart). That is still about ten times worse than in the developed world. Officials say safety conditions remain "grim". But the coal industry is also labour-intensive. China has 5.8m miners; America, the world's second-largest producer, has only 80,000. Measured by deaths per 100,000 coalminers, China's annual rate of 16 compares favorably with a total of 20 deaths in America in 2013.
There has already been clear improvement, The government has cracked down for a variety of reasons. One is embarrassment. Soaring deaths a decade ago tarnished the party's image even as it boasted of its efforts to create a "harmonious society". With the spread of the internet and social media it became much more difficult for censors to cover up accidents. Tim Wright of Sheffield University notes that mentions of "coal-mine safety" spiked upwards from 2001.
Safety also improved because the government closed lots of small mines, which happened to be the deadliest ones. It wanted to concentrate the industry in the hands of larger, more efficient and supposedly less dirty state-owned firms. Remaining township mines are now safer. At the government's urging, state-owned coal firms have made big investments in safety after years of neglect.
Harsher penalties for the operators of accident-prone mines, and their local-government supervisors, may have helped too. Alas, punishing officials on a per-death basis may have the perverse effect of encouraging cover-ups. But a fierce campaign against corruption may have curbed such practices.
As China's economy now begins to slow, coal prices are falling. This may make it easier to prise dangerous mines from the hands of private and local-government operators. To help reduce excess capacity, the government this year banned the opening of new mines in some parts of the country. In helping to reduce the number of deaths, economic headwinds may prove a blessing.