As China prepares to release its second-quarter and first-half economic data this week – with markets generally expecting performance to have softened – manufacturers in its southern Pearl River Delta region offer a nuanced picture.While official manufacturing data for June showed continued expansion, electronics exporters in the region – one of China’s biggest industrial areas and a bellwether for the national economy – said last week that a pickup in orders had yet to lift their bottom lines.Rising raw material costs, tougher payment terms set by vendors, and persistent price competition were squeezing profits, they said.Manufacturers said that despite strong export demand, particularly from the US, those pressures could stymie efforts to increase sales and fund new investments or hiring.The question being asked on factory floors is whether stimulus measures could ease the cost pressures eating into margins, with all eyes on the midyear Politburo meeting, expected to be held later this month.At the July meeting of the Politburo – a major decision-making body of the ruling Communist Party – policymakers typically assess the country’s first-half economic performance and chart the course for the remainder of the year.