"We are all in this together." Thus spoke George Osborne, Britain's Chancellor of the Exchequer in 2010, to justify the austerity policies of the Conservative and Liberal Democrat coalition. He meant that the burden of austerity should be shared right across society. Whether or not his government delivered on that promise, it is true in another sense. The world increasingly works as a single economy, and individual nations are losing their power to manage their own microclimates.
This is the message of a very interesting article in last week's Economist. The immediate point of the article is to criticise Germany for its persistent and large current account surplus. This is making it harder for its neighbours, especially in the Eurozone. It is sucking demand out of the European economy; meanwhile, through its strong advocacy of budget discipline, Germany is making it very hard for other European countries to make up the shortfall, especially in countries like Greece, who arguably need it the most. This is an old story, which has been pursued many times by commentators such as the FT's Martin Wolf; some recent IMF research just underlines the matter.
But the article goes on to make a wider point. There seems to be a wider contagion problem in global demand. In weak economies, demand falls, and one way or another this reduces current account deficits and increases surpluses. Weak demand directly reduces imports; a weak currency or pressure on wages makes exports more competitive. Greece has turned a spectacular deficit in 2009 into a significant surplus. But this reduces demand in healthier economies, spreading the weakness. There arises a cycle of doom, unless surplus economies, like Germany, start borrowing to stoke up demand. But there is little political imperative to do so: there are political benefits to surplus, which tend to strengthen the hands of ruling elites and allow greater stability. Financially secure deficit countries, like the US and Britain, might also do a bit to stoke up demand - but ultimately their deficits limit their capacity to do so. Sustained fiscal stimulus, as practised by Japan for example, really requires a current account surplus.
But this is only the start of global interconnectedness. Both inflation and interest rates seem to be determined more by world markets than domestic policy - in the developed world at least. Hence a remarkable convergence between nations as far a apart as Japan, Britain and the USA. The penny does not seem to have dropped amongst many economic commentators, though.
What accounts for this degree of interconnectedness? It was not so evident in the 1970s, when there was much more divergence between the major economies: compare that decade for Britain, Germany, Japan and the US. The most important single driver was the collapse of the Bretton Woods system of global capital controls, and the liberation of currencies to float where markets took them. There is a paradox here: these freedoms should in principle make governments more independent. Alas there are no free lunches in economics.
Free capital movement frees up countries to run large current account surpluses and deficits. In a system of limited capital flows a surplus country had a problem of what to do with its foreign currency earnings. Meanwhile deficit countries can find it quite hard to find the money to pay for imports. The decades before the 1970s were dominated by balance of trade crises. Older Britons will remember the devaluation crisis in 1967 (which I still remember though I was but 9 years old - such was its impact). In 1956 the US abruptly ended Britain's adventure in Suez as it threatened to cut support for the UK currency.
Now governments find it much easier to ride imbalances of trade, though eventually deficit countries run out of road (Argentina comes to mind); surplus countries find things much easier, except every so often their foreign financial holdings can take a hit.
But the freedom to run up surpluses and deficits has also given rise to a dependency on global capital markets to fund businesses, governments and private individuals (typically to fund house purchases). The financial crash of 2008-2009 was only the nastiest episode of many, where events in one country shook economies far away. The British government of the time could not believe that a tumble in US sub-prime real estate prices could totally derail their own economy. Labour politicians still put on an air of injured innocence - though Britain's dependence on global capital flows was positively reckless.
There has been an important second development, apart from the freedom of global capital, though: the rise of global supply chains, and of China in particular. It is hard to underestimate the impact of global trade and global competition on the world economy. This has led to the biggest reduction in world poverty in human history - but the impact on traditional industrial areas of the developed world has not been so benign. One of the most important consequences has been to change the dynamics of price movements in both the labour and goods markets. A rise in the price of goods does not automatically lead to a rise in wages, as it used to. In the 1990s and 2000s economists attributed the remarkable stability of inflation in the developed world to sound monetary policy. But the globalisation of supply chains was a large factor - which may have allowed monetary policy to be looser than it should have been, contributing to the eventual crash.
All this leads to a key question in the current world economy. Does the generally disappointing level of demand in the developed world arise from the lack of coordination of economic policy, rather than deeper factors like demographics and changes to technology? The recent G20 meeting seemed to suggest as much, but no concerted action was agreed upon. I have always suggested that deeper factors where more significant - but Economist article poses troubling questions.
And then there is a question of economic strategy. A global economic government is clearly out of the question. We only have to look at the struggles of the Eurozone to see that. So is there a way of regaining control of our microclimates, without throwing away the gains from world trade? This applies, incidentally, not just to countries, but regions within countries. Clearly the answer is not the free movement of currencies, as some Anglo-Saxon commentators like to think. But we do need to think about how to manage the movement of capital better, both internationally and within our countries.