China's infrastructure investment spending is already growing at record levels and has little room to increase, according to Alex Wolf, emerging markets economist, Standard Life Investments. Due to investment dwindling across most other sectors, and the fact that the private sector now accounts for roughly two-thirds of investment spending, Beijing has a diminished ability to significantly boost growth. With declining investment across most sectors, it is only a matter of time before wages, employment and consumption exhibit more strain, writes Wolf. A response focused on infrastructure stimulus may marginally support growth in the short term - but as the impact shrinks, China will be out of options.