Economist: A DESOLATE scene surrounds Little Zhangs Tyre Repair in the dusty rock-mining township of Shijing, in the northern province of Hebei. Zhang Minsheng, the owner, still gets some business from passing traffic. But the recent closure of nearby rock quarries, because of air-pollution restrictions, has taken its toll. He reckons his monthly income has fallen by 30-40% to around 4,000 yuan ($640). Next door a wholesale coal business has closed. So too have a small family-owned barbecue restaurant and...