I have a memory picture of an urban highway in Shenzen, southern China. Recently built, with abundant flowering shrubs planted along its central reservation, it was lined as far as the eye could see by uncountable apartment towers, many of them unfinished. This was 2009 and it was my first glimpse of the debt-fuelled property bonanza that had begun to grip the Chinese economy – alongside the export-led manufacturing boom that was also plainly visible, thanks to satellite maps of the vast agglomeration of factories surrounding the new-rich residential areas.