Paul Krugman is absolutely right that one of the rationales for the IMF and others framing fiscal policy in terms of the ‘speed of consolidation’ is a belief that left to themselves politicians will always and everywhere let debt rise. As he points out, the facts for the US tell a rather different story. Here I want to add a couple of additional points by looking at experience outside the US.
As should be well known by now, UK government debt was over a 100% of GDP between the wars, but declined rapidly and consistently to 50% from the second war to the mid 1970s. (See here, or this useful UK site.) The chart below, based on OBR data, takes up the story since then.
|UK Debt to GDP ratio (%)
So perhaps the simplest description is that debt to GDP began to level off at around 40% of GDP (which was the target from 1998 to 2008), until the Great Recession hit. There is a lot of interesting detail here, but that would distract from the main point, which is that the UK is another clear counterexample to the idea that governments always let their debt rise.
However deficit bias is not a figment of international policymakers imagination. As I note here with Lars Calmfors, and others have noted before us, government debt in the OECD area as a whole almost doubled (40% to 75%) between the mid-70s and the mid-90s. This deficit bias came not from the UK, and not much from the US, but from Europe and Japan. (To see data on individual countries or country groups, see this nice IMF resource. )
So the only reasonable conclusion is that deficit bias is a problem, but not one that afflicts every government at all times. As Lars and I document, there have been various studies that have attempted to draw lessons from this diversity of experience: for example coalition governments may be more prone to deficit bias, but institutional set-ups where the finance ministry is strong less prone. My own support for fiscal councils partly stems from a desire to look for an institutional mechanism to help counter deficit bias. There is no magic bullet here, and institutional solutions will differ depending on national constitutional characteristics.
If this last point seems obviously reasonable, then lets change the dimension from across countries to across time and states of the world. While we may observe a tendency towards deficit bias in normal times, in times like now when government debt is high we seem to be observing a quite different bias - a bias towards austerity. The apparent consensus of 2008/9 that we needed fiscal stimulus looks like the aberration rather than the rule. An international organisation wanting to push sound economics needs to be doing more than arguing for a slower speed of consolidation. By advocating fiscal consolidation when the opposite is required you risk discrediting your advice at other times.
Here is another analogy. Doctors quite rightly encourage us to take more exercise. That is because we have a tendency to sit around too much, but this bias is not universal across people types or ages. Yet when we catch flu, the doctor prescribes rest, not exercise. Indeed, a good doctor may well be specific about the length of rest required, because they know too many patients may think they are better before they have fully recovered. If a doctor told us that while we had flu we should cut down from 30 minutes exercise to 15 or 10, we might begin to doubt their credentials.
 To get the debt series, click on the blue subheading ‘Real GDP growth’.