In early November, China’s most populous province launched its biggest ever consumer subsidy programme, with the government pledging to commit 3.5 billion yuan (US$492 million) to offer discounts on a slew of products: from smartphones to snowboards.Guangdong’s scheme is the latest attempt by Chinese authorities to use consumption vouchers to boost domestic spending – a campaign that is key to China’s efforts to shore up growth and rebalance its economy amid the ongoing US trade war.But on the...