If history is any guide - and it often isn’t - the threat of food price controls in China is a sell signal for equity investors. Steven Sun of HSBC has looked at what happened to Chinese stocks when price controls were last imposed, in 2008. And he doesn’t like what he sees - equities plunged 14 per cent in the three months after food price controls started and 22 per cent in the three months after coal price controls were introduced. This time a 10-15 per cent decline is likely, Sun says. That may not sound like a lot, but the volatile Chinese market has a tendency to overshoot such targets. Maybe this is what HSBC’s own chief executive meant when he said earlier this month that emerging markets were in for a bumpy ride. “The risk of price controls is looming large”, says Sun’s report. He warns that the central bank is “behind the curve” in terms of policy actions because of its pro-growth bias and divergent views among ministries. QE2 could force price controls before the Chinese New Year, when shoppers tend to splurge. HSBC forecasts that Hang Seng at 22,000 at the year-end (versus 23,214 today) and the Shanghai Composite at 2,800 (versus 2,838.9 today). The only consolation for investors is that Sun’s forecast would appear to include at least some of the 11-per-cent fall already seen in Shanghai in the past week. The report follows closely another gloom note by Sun earlier this week, in which he warned - as he does here - that QE2 “is fuelling inflation and asset bubbles in emerging markets”. Meanwhile, Nomura, another long-term bull on China, has also turned bearish in the face of the growing threat of inflation. Sean Darby, the widely-respected equity strategist, writes: 'The likelihood of a reintroduction of price controls on food is growing. The recent run-up in agriculture prices worldwide and signs of hoarding appear to have pushed the authorities to reconsider draconian measures. Coupled with rationing of electricity supply and rising demand for diesel, inflationary pressures are becoming far more pronounced. While authorities are resisting the call for tightening, rising commodity prices and potential weather disruptions are likely to be unfavourable.'