Why Modern Monetary Theory is Wrong About Government Debt

I’ve taken some criticism — particularly from advocates of modern monetary theory and sectoral balances and all that — for using total debt rather than just private debt in my work.

The modern monetary theory line (in one sentence, and also in video form) is that government debt levels are nothing to worry about, because governments are the issuer of the currency, and can always print more.

This evokes the words of Alan Greenspan:

The United States can pay any debt it has because we can always print money to do that. So there is zero probability of default.

Of course, the point I am trying to make in worrying about total debt levels is not the danger of mass default (although certainly default cascades a la Lehman are a concern in any interconnective financial system), but that large debt loads can lead to painful spells of deleveraging and economic depression as has occurred in Japan for most of the last twenty years:


Of course, before the crisis in America (as was the case in Japan at the beginning of their crisis) government debt was not really a great contributor to the total debt level, meaning that the total debt graph looks far more similar to the private debt line than the public debt line, which means that when I talk about the dangers of growing total debt I am talking much more about private debt than public debt:


But what Japan empirically illustrates is the fact that all debt matters. Japan’s private debt levels have reset to below the pre-crisis norm, yet the economy remains depressed while public debt continues to climb (both in absolute terms, and as a percentage of GDP). If excessive private debt was the sole factor in Japan’s depression, Japan would have recovered long ago. What we have seen in Japan has been the transfer of the debt load from the private sector to the public, with only a relative small level of net deleveraging.

And high and growing public sector deficits often lead to contractionary tax hikes and spending cuts. This happened time and again during Japan’s lost decades. Peter Tasker of the Financial Times writes:

When Japan’s bubble economy imploded in the early 1990s, public finances were in surplus and government debt was a mere 20 per cent of gross domestic product. Twenty years on, the government is running a yawning deficit and gross public debt has swollen to a sumo-sized 200 per cent of GDP.

How did it get from there to here? Not by lavish public spending, as is sometimes assumed. Japan’s experiment with Keynesian-style public works programmes ended in 1997. True, they had failed to trigger durable economic recovery. But the alternative hypothesis – that fiscal and monetary virtue would be enough – proved woefully mistaken. Economic growth had been positive in the first half of the “lost decade”, but after the government raised consumption tax in 1998 any momentum vanished. Today Japan’s nominal GDP is lower than in 1992.

The real cause of fiscal deterioration was the damage done to tax revenues by this protracted slump. Central government outlays as a percentage of GDP are no higher now than in the early 1980s, but the tax take has fallen by 5 per cent of GDP since 1989, the year that consumption taxes were introduced.

A rise in debt relative to income has historically tended to lead to contractionary deleveraging irrespective of whether the debt is public or private.

The notion at the heart of modern monetary theory that governments that control their own currency do not have to engage in contractionary deleveraging remains largely ignored. Just because nations can (in a worst case scenario) always print money to pay their debt, doesn’t mean that they will always print money to pay their debt. They will often choose to adopt an austerity program (as is often mandated by the IMF), or default outright instead (as happened in Russia in the 1990s).

And what governments cannot guarantee is that the money they print will have value. This is determined by market participants. In the real economy people in general and creditors (and Germans) in particular are very afraid of inflation and increases in the money supply. History is littered with currency collapses, where citizens have lost confidence in the currency (although in truth most hyperinflations have occurred after some great shock to the real economy like a war or famine, and not solely as a result of excessive money printing).

And there has always been a significant danger of currency, trade and political retaliations by creditors and creditor nations, as a result of the perception of “money printing”. Many, many wars have been fought over national debts, and over currencies and their devaluation. One only has to look at China’s frustrated rhetoric regarding America’s various monetary expansions, the fact that many Eurasian creditor nations are moving away from the dollar as a reserve currency, as well as the growth of American-Chinese trade measures and retaliations, to see how policy of a far lesser order than the sort of thing advocated in modern monetary theory can exacerbate frictions in the global currency system (although nothing bad has come to pass yet).

Governments controlling their own currencies are likely to continue to defy the prescriptions of the modern monetary theorists for years to come. And that means that expansionary increases in government debt relative to the underlying economy will continue to be a prelude to contractionary deleveraging, just as is the case with the private sector. All debt matters.