China’s hopes for a consumption boom may depend less on stimulus or wealthy households and more on improving living standards for 131 million migrant workers in its cities – a shift that could unlock spending equivalent to about 0.5 per cent of the country’s gross domestic product, according to HSBC.In a report released on Thursday, analysts at the bank projected that the world would add about 1.2 billion middle- and high-income consumers by 2050, with Asia accounting for 77 per cent of the...