China’s consumer prices slipped back into decline in August, highlighting persistent deflationary pressures, while a narrower drop in factory-gate prices suggested Beijing’s “anti-involution” campaign may be starting to take hold.The national consumer price index (CPI), a key gauge of inflation, fell 0.4 per cent year on year last month, according to data released by the National Bureau of Statistics on Wednesday.The reading fell short of market expectations after a poll by financial provider...