Fiscal policy can do more heavy lifting when monetary policy alone is no longer enough. Even without any coordination, governments have room to borrow and invest more – especially in a low interest rate environment – to effectively stir activity. We have argued that there has not been enough government spending globally on infrastructure, education, renewable energy or other technologies to lift total factor productivity growth back to its pre-crisis trends and boost potential growth.
The low interest rate environment increases fiscal space not only by making it cheaper to borrow, but also makes it possible for some governments to grow out of the increased debt. The ratio of interest expense to revenue for developed market (DM) governments is lower on average now than it was before the global financial crisis, even though debt levels are considerably higher. So as long as risk free rates stay below the return on capital and trend growth, it is possible to increase deficits and still see debt-to-GDP ratios fall (Blanchard 2019, Furman and Summers 2019). The chart above shows how this is true for many DM countries.
There are good reasons to expect an environment favourable to fiscal policy to persist: the deep-rooted forces underlying the global saving glut will not change quickly on their own or will need material changes to be affected. That appears to be the market’s belief.
Yet there is no guarantee this favourable wedge between interest rates and trend growth would persist in the face of a major fiscal expansion. The strength and persistence of global precautionary saving pushed real interest rates below growth, driven by the decline in both neutral rates and the term premium, according to our estimates. But a significant increase in borrowing by governments globally could absorb part or all of this saving glut, pushing real interest rates towards or even above growth.
Furthermore, with debt to GDP ratios reaching record highs, it would not take much of a shock to growth or interest rates for the debt ratio to balloon and spark concerns about debt sustainability. Hence high existing debt levels mean fiscal policy is vulnerable to even transitory interest rate spikes. Such a surge in rates could damage the fiscal policy space. This could arise from a so-called sudden stop: a temporary drying up of liquidity due to concerns about debt sustainability or losing reserve currency status.
Typically countries that issue debt in their own currency can sustain higher debt levels and have more flexibility than countries that cannot. Yet countries borrowing in their own currency cannot completely avoid a surge in rates. If debt is on an unsustainable trajectory, the central bank can intervene by either increasing the monetary base by printing money or restarting QE. In the first case, runaway inflation would likely result at some point. In the second, it is important to realise that QE does not improve the government’s solvency: as the central bank issues reserves to buy bonds, the consolidated balance sheet of the government sector – including the central bank – is unchanged.
Record debt levels might also stoke expectations that taxes will be raised, or benefits reduced, in the future. Such expectations could reduce current private sector spending and reduce the effectiveness of any public spending increase, a phenomenon known as Ricardian equivalence.
In the final blog in this series, I will outline our proposed solution to the problems facing central banks. You can read also read our full paper on the subject: Dealing with the next downturn.