Higher debt, slower growth and an overvalued currency - now subject to speculation - produced China's stock market crash. Now rich Chinese and foreign investors are trying to get their money out of China or to convert savings into dollars - held abroad. China's wealthy class are moving about $100bn a month out of China. As Chinese dollar reserves are about $3.3trn and around half of that is needed to cover imports, if capital flight continues at the current rate, Chinese dollar reserves will be exhausted in about 18 months. Clearly such economic sabotage must be stopped.

The extent that China has opened its economy made it susceptible to currency and financial speculation. Although a weaker yuan boosted exports, it also encouraged rich individuals and Chinese companies to buy more dollars, legally and illegally. Last year the authorities propped up the stock market with extra credit and state-owned banks bought stocks. However, this fuelled even more debt. This policy was then reversed, provoking a stock market crash and credit squeeze.

Many Western economists predict that China will suffer a "hard landing" or economic slump, capitalist-style, and this will add to already diving emerging economies and drive the world into slump. But China is not a capitalist economy. State ownership remains dominant in the commanding heights of heavy industry, energy, telecommunications, financial services and investment. But China has opened its economy to the pressures of capitalism, particularly in trade and capital flows, and so it is more vulnerable to crises. Some Chinese economists agree with the World Bank and others who want to "liberalize" the financial sector and make China a respected part of the international financial "community." Events show that this is poor counsel.

Yes, the world is slowing down, and a long period of below-trend growth is still operating. Last week, the World Bank revealed that developing economies grew just 3.7 percent in 2015, the slowest since 2001 and two percentage points below the average 6.3 percent growth during the boom years between 2000 and 2008.

The IMF chief Christine Lagarde reckons that developing countries face "new reality" of lower growth. "Growth rates are down, and cyclical and structural forces have undermined the traditional growth paradigm. On current forecasts, the emerging world will converge to advanced-economy income levels at less than two-thirds the pace we had predicted just a decade ago. This is cause for concern." A 1 percent slowdown in emerging markets would cause already weak growth in advanced countries to slow by about 0.2 percentage points, Ms Lagarde said.