Tag: primary balance

The following blog is inspired by my teaching of macroeconomic issues to my final year students at Aston University. In the classes we’ve been discussing important aspects of monetary and fiscal policy design. What has become clear to me and my students is that the trade-offs which characterise the discipline of economics are certainly alive and well in the current environment in which monetary and fiscal policy choices are being made.

To demonstrate this we consider here some of the discussions we’ve had in class around central bank independence and monetary policy mandates. We’ve also looked at fiscal policy. Here we’ve examined the state of the public finances and the importance that seems to be attached to debt stabilisation and the imposition of debt rules.

Delegation and central bank mandates

My teaching this term began by introducing my students to one of the most important and influential monetary policy models. This is the model of Kydland and Prescott. Their model, published in the Journal of Political Economy in 1977 has become the theoretical bedrock for the modern-day operational independence of central banks.1

The model explores how systemically high inflation can become established in economies when policymakers have the political incentive to lower unemployment or increase output above its long-run equilibrium value. This may be the case if governments operate monetary policy rather than the central bank (of if the central bank operates monetary policy but follows government objectives). By adopting expansionary monetary policy, governments can increase their popularity.

But this is likely to be short-lived, as any increased economic activity will only be temporary (assuming that the natural-rate hypothesis holds). Soon, inflation will rise.

But, if an election is on the horizon, there may be enough time to boost output and employment before inflation rises. In other words, an expectations-augmented Phillips curve may present governments with an incentive to loosen monetary policy and worry about the inflation consequences after the election.

However, the resulting ‘inflation surprise’ through the loosening of monetary policy means a fall in real pay and therefore in purchasing power. If people suspect that governments will be tempted to loosen policy, they will keep their expectations of inflation higher than the socially optimal inflation rate. Consequently, low-inflation targets lack credibility when governments have the temptation to loosen monetary policy. Such targets are time-inconsistent because governments have an incentive to renege and deliver higher inflation through a looser monetary policy. The result is an inflation bias.

Central bank independence
To prevent this inflationary bias arising, many central banks around the world have been given some form of operational independence with a mandate centred around an inflation-rate target. By delegating monetary policy to a more conservative central bank, the problem of inflationary bias can be addressed.

Yet central bank independence is not without its own issues and this has been an important part of the discussions with my students. Today, many economies are continuing to experience the effects of the inflationary shocks that began in 2021 (see Chart 1 for the UK CPI inflation rate: click here for a PowerPoint). The question is whether the appointment of a conservative or hard-nosed hawkish central banker trades off the stabilisation of inflation for greater volatility in output or unemployment.

The inflation–output stabilisation trade-off is closely associated with the works of Kenneth Rogoff2 and John Taylor3. The latter is known for his monetary policy rule, which has become known as the ‘Taylor rule’. This advocates that a rules-based central bank ought to place weight on both inflation and output stabilisation.

This is not without its own issues, however, since, by also placing weight on output stabilisation, we are again introducing the possibility of greater inflationary bias in policy making. Hence, while the act of delegation and a rules- or target-based approach may mitigate the extent of the bias relative to that in the Kydland and Prescott model, there nonetheless still remain issues around the design of the optimal framework for the conduct of monetary policy.

Indeed, the announcement that the UK had moved into recession in the last two quarters of 2023 can be seen as evidence that an otherwise abstract theoretical trade-off between inflation and output stabilisation is actually very real.

My classroom discussions have also shown how economic theory struggles to identify an optimal inflation-rate target. Beyond accepting that a low and stable inflation rate is desirable, it is difficult to address fully the student who asks what is so special about a 2% inflation target. Would not a 3% target, for example, be preferable, they might ask?

Whilst this may sound somewhat trivial, it has real-world consequences. In a world that now seems to be characterised by greater supply-side volatility and by more frequent inflation shocks than we were used to in recent history, might a higher inflation rate target be preferable? Certainly, one could argue that, with an inflation–output stabilisation trade-off, there is the possibility that monetary policy could be unduly restrictive in our potential new macroeconomic reality. Hence, we might come to see governments and central banks in the near future revisiting the mandates that frame the operation of their monetary policy. Time will tell.

Fiscal policy and debt stabilisation

The second topic area that I have been discussing in my final-year macroeconomics classes has centred around fiscal policy and the state of the public finances. The context for this is that we have seen a significant increase in public debt-to-GDP ratios over the past couple of decades as the public sector has attempted to absorb significant economic shocks. These include the global financial crisis of 2007–8, the COVID-19 pandemic and the cost-of-living crisis. These interventions in the case of the UK have seen its public debt-to-GDP ratio more than triple since the early 2000s to close to 100% (see Chart 2: click here for a PowerPoint).

Understandably, given the stresses placed on the public finances, economists have increasingly debated issues around debt sustainability. These debates have been mirrored by politicians and policymakers. A key question is whether to have a public debt rule. The UK has in recent years adopted such a rule. The arguments for a rule centre on ensuring sound public finances and maintaining the confidence of investors to purchases public debt. A debt rule therefore places a discipline on fiscal policy, with implications for taxation and spending.

How easy it is to stick to a debt rule depends on three key factors. It will be harder to stick to the rule:

  • The higher the current debt-to-GDP ratio and hence the more it needs to be reduced to meet the rule.
  • The higher the rate of interest and hence the greater the cost of servicing the public debt.
  • The lower the rate of economic growth and hence the less quickly will tax revenues rise.

With a given debt-to-GDP ratio, a given average interest rate payable on its debt, and a given rate of economic growth, we can determine the primary fiscal balance relative to GDP a government would need to meet for the debt-to-GDP ratio to remain stable. This is known as the ‘debt-stabilising primary balance’. The primary balance is the difference between a government’s receipts and its expenditures less the interest payments on its debt.

This fiscal arithmetic is important in determining a government’s fiscal choices. It shows the implications for spending and taxation. These implications become ever more important and impactful on people, businesses, and society when the fiscal arithmetic becomes less favourable. This is a situation that appears to be increasingly the case for many countries, including the UK, as the rate of interest on public debt rises relative to a country’s rate of economic growth. As this happens, governments are increasingly required to run healthier primary balances. This of course implies a tightening of their fiscal stance.

Hence, the fiscal conversations with my students have focused on both the benefits and the costs of debt-stabilisation. In respect of the costs, a few issues have arisen.

First, as with the inflation-rate target, it is hard to identify an optimal public debt-to-GDP ratio number. While the fiscal arithmetic may offer some clue, it is not straightforward to address the question as to whether a debt-to-GDP ratio of say 100% or 120% would be excessive for the UK.

Second, it is possible that the debt stabilisation itself can make the fiscal arithmetic of debt stabilisation more difficult. This occurs if fiscal consolidation itself hinders long-term economic growth, which then makes the fiscal arithmetic more difficult. This again points to the difficulties in designing policy frameworks, whether they be for monetary or fiscal policy.

Third, a focus on debt stabilisation alone ignores the fact that there are two sides to any sector’s balance sheet. It would be very unusual when assessing the well-being of businesses or households if we were to ignore the asset side of their balance sheet. Yet, this is precisely the danger of focusing on public debt at the exclusion of what fiscal choices can mean for public-sector assets, from which we all can potentially benefit. Hence, some would suggest a more balanced approach to assessing the soundness of the public finances might involve a net worth (assets less liabilities) measure. This has parallels with the debates around whether mandates of central banks should be broader.

Applications in macroeconomics

What my teaching of a topics-based macroeconomics module this term has vividly demonstrated is that concepts, theories, and models come alive, and are capable of being understood better, when they are used to shine a light on real-world issues. The light being shone on monetary and fiscal policy in today’s turbulent macroeconomic environment is perhaps understandably very bright.

Indeed, the light being shone on fiscal policy in the UK and some other countries facing an upcoming election, is intensified further with the state of the public finances shaping much of the public discourse on fiscal choices. Hopefully, my students will continue to debate these important issues beyond their graduation, stressing their importance for people’s lives and, in doing so, going beyond the abstract.

References

  1. Rules rather than discretion: The inconsistency of optimal plans
    The Journal of Political Economy, Finn E Kydland and Edward C. Prescott (1977, 85(3), pp 473–92)
  2. The optimal degree of commitment to an intermediate monetary target
    Quarterly Journal of Economics, Kenneth Rogoff (November 1985, 100(4), pp 1169–89)
  3. Discretion versus policy rules in practice
    Carnegie-Rochester Conference Series on Public Policy, John B Taylor (December 1993, 39, pp 195–214)

Articles

Questions

  1. What is meant by time-inconsistent monetary policy announcements? How has this concept been important for the way in which many central banks now conduct monetary policy?
  2. What is meant by a ‘conservative’ central banker? Why is the appointment of this type of central banker thought to be important in affecting inflation?
  3. What is the contemporary macroeconomic relevance of the inflation–output (or inflation–unemployment) stabilisation trade-off?
  4. How is the primary balance different from the actual budget balance?
  5. What do you understand by the concept of ‘the fiscal arithmetic’. Explain how each element of the fiscal arithmetic affects the debt-stabilising primary balance?
  6. Analyse the costs of benefits of a debt-based fiscal rule.

The past decade or so has seen large-scale economic turbulence. As we saw in the blog Fiscal impulses, governments have responded with large fiscal interventions. The COVID-19 pandemic, for example, led to a positive fiscal impulse in the UK in 2020, as measured by the change in the structural primary balance, of over 12 per cent of national income.

The scale of these interventions has led to a significant increase in the public-sector debt-to-GDP ratio in many countries. The recent interest rates hikes arising from central banks responding to inflationary pressures have put additional pressure on the financial well-being of governments, not least on the financing of their debt. Here we discuss these pressures in the context of the ‘r g’ rule of sustainable public debt.

Public-sector debt and borrowing

Chart 1 shows the path of UK public-sector net debt and net borrowing, as percentages of GDP, since 1990. Debt is a stock concept and is the result of accumulated flows of past borrowing. Net debt is simply gross debt less liquid financial assets, which mainly consist of foreign exchange reserves and cash deposits. Net borrowing is the headline measure of the sector’s deficit and is based on when expenditures and receipts (largely taxation) are recorded rather than when cash is actually paid or received. (Click here for a PowerPoint of Chart 1)

Chart 1 shows the impact of the fiscal interventions associated with the global financial crisis and the COVID-19 pandemic, when net borrowing rose to 10 per cent and 15 per cent of GDP respectively. The former contributed to the debt-to-GDP ratio rising from 35.6 per cent in 2007/8 to 81.6 per cent in 2014/15, while the pandemic and subsequent cost-of-living interventions contributed to the ratio rising from 85.2 per cent in 2019/20 to around 98 per cent in 2023/24.

Sustainability of the public finances

The ratcheting up of debt levels affects debt servicing costs and hence the budgetary position of government. Yet the recent increases in interest rates also raise the costs faced by governments in financing future deficits or refinancing existing debts that are due to mature. In addition, a continuation of the low economic growth that has beset the UK economy since the global financial crisis also has implications for the burden imposed on the public sector by its debts, and hence the sustainability of the public finances. After all, low growth has implications for spending commitments, and, of course, the flow of receipts.

The analysis therefore implies that the sustainability of public-sector debt is dependent on at least three factors: existing debt levels, the implied average interest rate facing the public sector on its debts, and the rate of economic growth. These three factors turn out to underpin a well-known rule relating to the fiscal arithmetic of public-sector debt. The rule is sometimes known as the ‘r g’ rule (i.e. the interest rate minus the growth rate).

Underpinning the fiscal arithmetic that determines the path of public-sector debt is the concept of the ‘primary balance’. This is the difference between the sector’s receipts and its expenditures less its debt interest payments. A primary surplus (a positive primary balance) means that receipts exceed expenditures less debt interest payments, whereas a primary deficit (a negative primary balance) means that receipts fall short. The fiscal arithmetic necessary to prevent the debt-to-GDP ratio rising produces the following stable debt equation or ‘r g’ rule:

On the left-hand side of the stable debt equation is the required primary surplus (PS) to GDP (Y) ratio. Moving to the right-hand side, the first term is the existing debt-to-GDP ratio (D/Y). The second term ‘r g’, is the differential between the average implied interest rate the government pays on its debt and the growth rate of the economy. These terms can be expressed in either nominal or real terms as this does not affect the differential.

To illustrate the rule consider a country whose existing debt-to-GDP ratio is 1 (i.e. 100 per cent) and the ‘r g’ differential is 0.02 (2 percentage points). In this scenario they would need to run a primary surplus to GDP ratio of 0.02 (i.e. 2 percent of GDP).

The ‘r g‘ differential

The ‘r g’ differential reflects macroeconomic and financial conditions. The fiscal arithmetic shows that these are important for the dynamics of public-sector debt. The fiscal arithmetic is straightforward when r = g as any primary deficit will cause the debt-to-GDP ratio to rise, while a primary surplus will cause the ratio to fall. The larger is g relative to r the more favourable are the conditions for the path of debt. Importantly, if the differential is negative (r < g), it is possible for the public sector to run a primary deficit, up to the amount that the stable debt equation permits.

Consider Charts 2 and 3 to understand how the ‘r g’ differential has affected debt sustainability in the UK since 1990. Chart 2 plots the implied yield on 10-year government bonds, alongside the annual rate of nominal growth (click here for a PowerPoint). As John explains in his blog The bond roller coaster, the yield is calculated as the coupon rate that would have to be paid for the market price of a bond to equal its face value. Over the period, the average annual nominal growth rate was 4.5 per cent, while the implied interest rate was almost identical at 4.6 per cent. The average annual rate of CPI inflation over this period was 2.8 per cent.

Chart 3 plots the ‘r g’ differential which is simply the difference between the two series in Chart 2, along with a 12-month rolling average of the differential to help show better the direction of the differential by smoothing out some of the short-term volatility (click here for a PowerPoint). The differential across the period is a mere 0.1 percentage points implying that macroeconomic and financial conditions have typically been neutral in supporting debt sustainability. However, this does mask some significant changes across the period.

We observe a general downward trend in the ‘r g’ differential from 1990 up to the time of the global financial crisis. Indeed between 2003 and 2007 we observe a favourable negative differential which helps to support the sustainability of public debt and therefore the well-being of the public finances. This downward trend of the ‘r g’ differential was interrupted by the financial crisis, driven by a significant contraction in economic activity. This led to a positive spike in the differential of over 7 percentage points.

Yet the negative differential resumed in 2010 and continued up to the pandemic. Again, this is indicative of the macroeconomic and financial environments being supportive of the public finances. It was, however, largely driven by low interest rates rather than by economic growth.

Consequently, the negative ‘r g’ differential meant that the public sector could continue to run primary deficits during the 2010s, despite the now much higher debt-to-GDP ratio. Yet, weak growth was placing limits on this. Chart 4 indeed shows that primary deficits fell across the decade (click here for a PowerPoint).

The pandemic and beyond

The pandemic saw the ‘r g’ differential again turn markedly positive, averaging 7 percentage points in the four quarters from Q2 of 2020. While the differential again turned negative, the debt-to-GDP ratio had also increased substantially because of large-scale fiscal interventions. This made the negative differential even more important for the sustainability of the public finances. The question is how long the negative differential can last.

Looking forward, the fiscal arithmetic is indeed uncertain and worryingly is likely to be less favourable. Interest rates have risen and, although inflationary pressures may be easing somewhat, interest rates are likely to remain much higher than during the past decade. Geopolitical tensions and global fragmentation pose future inflationary concerns and a further drag on growth.

As well as the short-term concerns over growth, there remain long-standing issues of low productivity which must be tackled if the growth of the UK economy’s potential output is to be raised. These concerns all point to the important ‘r g’ differential become increasingly less negative, if not positive. If so the fiscal arithmetic could mean increasingly hard maths for policymakers.

Articles

Data

Questions

  1. What is meant by each of the following terms: (a) net borrowing; (b) primary deficit; (c) net debt?
  2. Explain how the following affect the path of the public-sector debt-to-GDP ratio: (a) interest rates; (b) economic growth; (c) the existing debt-to-GDP ratio.
  3. Which factors during the 2010s were affecting the fiscal arithmetic of public debt positively, and which negatively?
  4. Discuss the prospects for the fiscal arithmetic of public debt in the coming years.
  5. Assume that a country has an existing public-sector debt-to-GDP ratio of 60 percent.
    (a) Using the ‘rule of thumb’ for public debt dynamics, calculate the approximate primary balance it would need to run in the coming year if the expected average real interest rate on the debt were 3 per cent and real economic growth were 2 per cent?
    (b) Repeat (a) but now assume that real economic growth is expected to be 4 per cent.
    (c) Repeat (a) but now assume that the existing public-sector debt-to-GDP ratio is 120 per cent.
    (d) Using your results from (a) to (c) discuss the factors that affect the fiscal arithmetic of the growth of public-sector debt.