At least, is Ha Joon Chang an economist with at least a vague familiarity with finance and public markets? I ask because this piece of his is remarkably naive and ill informed:

According to the stock market, the UK economy is in a boom. Not just any old boom, but a historic one. On 28 October 2013, the FTSE 100 index hit 6,734, breaching the level achieved at the height of the economic boom before the 2008 global financial crisis (that was 6,730, recorded in October 2007). Since then, it has had ups and downs, but on 21 February 2014 the FTSE 100 climbed to a new height of 6,838. At this rate, it may soon surpass the highest ever level reached since the index began in 1984 – that was 6,930, recorded in December 1999, during the heady days of the dotcom bubble.

The current levels of share prices are extraordinary considering the UK economy has not yet recovered the ground lost since the 2008 crash; per capita income in the UK today is still lower than it was in 2007. And let us not forget that share prices back in 2007 were themselves definitely in bubble territory of the first order. The situation is even more worrying in the US. In March 2013, the Standard & Poor 500 stock market index reached the highest ever level, surpassing the 2007 peak (which was higher than the peak during the dotcom boom), despite the fact that the country's per capita income had not yet recovered to its 2007 level. Since then, the index has risen about 20%, although the US per capita income has not increased even by 2% during the same period. This is definitely the biggest stock market bubble in modern history.

Even more extraordinary than the inflated prices is that, unlike in the two previous share price booms, no one is offering a plausible narrative explaining why the evidently unsustainable levels of share prices are actually justified.

I quote at length so that none will think that I am distorting his position.

The problem with this joint statement, that both the UK and US stock markets are grossly over valued relative to the domestic economies is that, well, the US and UK stock markets are not actually reflective of the relative domestic economies. The perceptive will have noted that we are in a period of globalisation in fact:

This optimism is not just because the U.K. economy is showing signs of improvement -- the Office for Budget Responsibility upgraded its forecast for gross domestic product growth in 2013 from 0.6 percent to 1.4 percent -- there is an international aspect to the optimism. After all, 80 percent of earnings by FTSE 100 companies come from overseas, according to Credit Suisse.

And:

S&P 500: 2010 Global Sales, analysis recently released by Howard Silverblatt of Standard and Poor’s, shows that the percentage of sales from S&P 500 companies that report results from foreign operations show that overseas sales grew to an estimated 46 percent in 2010. That number was in the 30 percent range just a decade ago, according to data collected by the Bureau of Economic Analysis.

I don't claim that either of those percentages are wholly accurate nor canonical. Only that somethiing near a majority of S&P 500 earnings come from outside the US and the vast majority of FTSE 100 such from outside the UK. Making a comparison of these indices with the respective domestic economies a truly horrible piece of misvaluation.

For we are indeed in this era of globalisation and that global economy is growing like gangbusters as hundreds of millions, billions, climb up out of that historical peasant destitution. Meaning that the capitalist types are celebrating, according to your preference, either the money that can be exploited out of these newly rich or the money that is being made by aiding them in becoming the newly rich.

Then we come to the truly absurd:

The result, unfortunately, is that stock market bubbles of historic proportion are developing in the US and the UK, the two most important stock markets in the world, threatening to create yet another financial crash. One obvious way of dealing with these bubbles is to take the excessive liquidity that is inflating them out of the system through a combination of tighter monetary policy and better financial regulation against stock market speculation (such as a ban on shorting or restrictions on high-frequency trading).

Blimey. Robert Shiller's just been awarded the Nobel in economics partly for his pointing out that in order to prick a speculative bubble you want people to be able to go short in said asset. Banning shorting makes it only possible to bet long, increasing said bubble.

I would have hoped that an economist at Cambridge would at least be conversant with these two points....