China’s top tech hub, Shenzhen, saw retail sales grow by just 0.5 per cent year on year in the first quarter after reporting gross domestic product growth of 5.8 per cent for the same period, casting a spotlight on its unbalanced development as mortgage and living costs weigh heavily on residents’ sentiment.A policy analyst said the city, in southern China’s Guangdong province, could have already seen retail sales decline if not for the rising number of bargain-hunters from Hong Kong crossing...