5/4/19: Does Government Debt Matter? The Reality of Fiscal Multipliers

There has always been a lot of debate in economics about the effects of debt (especially sovereign debt) on growth and fiscal dynamics. And, despite numerous papers on the subject, the debate is far from settled.

Here is an interesting new study that looks at the effect high levels of government indebtedness have on the effectiveness of fiscal policy stimulus. The reason this topic is important is simple: fiscal policy can and is used to offset or smooth out recessionary shocks. The extent to which fiscal policy is effective in doing so (the impact expansionary fiscal policy may have on unemployment and output) can be varied across different economies and under different crises conditions. But, does this extent vary under different debt conditions?

In theory, the debt levels carried by a given sovereign can impact the size of fiscal multipliers (the effectiveness of fiscal policy) through two main channels:

1. The so-called Ricardian channel: a government with a weak fiscal position (high debt) deploying fiscal stimulus (an increase in public spending) can cause households to expect future tax increases. The result is that in economies with high public debt levels, deploying fiscal stimulus can trigger increased savings by households, reducing consumption, and lowering the size of fiscal policy multiplier.
2. An interest rate channel: when the government debt is high, so that the government fiscal position is weak, fiscal stimulus can increase concerns about sovereign credit risk amongst government bond holders and buyers. This can increase bond yields, raise borrowing costs, lower liquidity of bonds for the sovereign, but also increase cost of capital across the private sector. The result is the crowding out effect, whereby public spending crowds out private investment and credit-finance consumption.

In theory, both channels imply that fiscal policy is less effective when fiscal stimulus is implemented from a weak initial fiscal position (position of high starting government debt levels).

A new World Bank paper, authored by Huidrom, Raju and Kose, M. Ayhan and Lim, Jamus Jerome and Ohnsorge, Franziska, and titled "Why Do Fiscal Multipliers Depend on Fiscal Positions?" (March 2019, World Bank Policy Research Working Paper No. 8784: https://ssrn.com/abstract=3360142) considers the two theoretical channels operating simultaneously. Using data for 34 countries (19 advanced economies and 15 developing economies),  over 1Q 1980 through 1Q 2014, the authors show that "the fiscal position helps determine the size of the fiscal multipliers: estimated multipliers are systematically smaller when the fiscal position is weak (i.e. government debt is high).

Looking at the longer run panel in the chart above, fiscal multipliers rapidly reach into negative territory as Government debt rises to around 37-40 percent of GDP. Over a medium term horizon, of 2 years, multipliers hit negative values for debt levels above 75 percent of GDP.

Similar dynamics are confirmed in the chart below:

The authors subsequently "show that when a government with weak public finances conducts expansionary fiscal policy, the private sector scales back on consumption in anticipation of future tax pressures (Ricardian channel) and risk premia rise on mounting concerns about sovereign risk (interest rate channel)." In other words, high starting debt position does trigger both theoretical effects to reinforce each other.

This is an unpleasant arithmetic for uber-Keynesians who hold that fiscal policy is always effective in stimulating economic growth during periods of economic crises. The findings also support the view that the 'fiscal policy space' is indeed bounded by the reality of pre-crisis fiscal policy paths: there is no free lunch when it comes even to sovereign financing.