NYU London

As an academic discipline, Macroeconomics has been criticised for not predicting the Great Financial Crisis; for using simplistic, out-of-date models; for ignoring data that challenged stylised theories; and for failing to acknowledge that economic theory has little to offer without a clear, socio-political and historical context. The purpose of this course has been to counter such criticisms, not by reinventing the wheel but rather by showing that Macroeconomics, carefully and intelligently deployed, can offer helpful guidelines in addressing society’s key challenges for the 21st century.

In understanding the macro world around us we have deployed models. As we noted towards the beginning of the course, all models are wrong but some are useful. Models help citizens and their representatives to make better choices by organising thoughts, suggesting strategies, clarifying definitions and exposing assumptions. Accounting identities impose discipline as do long-run budget constraints – the issue of sustainability. Models require us to marshal facts and figures; more than that, to understand and interpret such data both critically and intelligently. In many cases, models can reveal unexpected consequences, forcing a rethink of strategies and policy options.

Initially we gained understanding of long-run growth processes through models developed by Solow and Romer. The classic Loanable Funds model provided additional insights. For business cycles, we have enlisted the help of multiplier-accelerator models, the Frisch-Slutsky paradigm and the AD-AS apparatus involving the IS curve, the Taylor Rule, the Phillips Curve as well as the Okun labour market relationship. Taking an international perspective we have extended our analysis to include exchange rates and capital flows. Specifically, we have deployed the Mundell-Fleming model and its extensions to embrace the realities of potential inflation and variable risk premia.

Models of expectations have extended our understanding of how the global economy works. Volatile beliefs, especially about an uncertain future, typically impact the present. Stability is no longer assured, a unique steady state might not exist; the world can be populated by multiple equilibria, bad as well as good. Efficient markets can become highly inefficient; recall Minsky’s ideas about the financial system. Crises can reflect bad luck, but often shocks are home-grown, endogenous responses to systemic frailties. Messy reality poses serious challenges for conventional macroeconomic analysis and these are explored in greater depth in two highly recommended books – Andrew Lo’s Adaptive Markets and William Janeway’s Doing Capitalism in the Innovation Economy.

The focus of our final session will be DSGE models that are widely used in central banks and elsewhere for forecasting and simulating macroeconomic processes. They are by no means the only game in town and alternative approaches – such as Agent Based Models and machine learning – are becoming increasingly popular. A key theme of the session is that you can never have enough models.

James Surowiecki’s Wisdom of Crowds and Scott Page’s The Difference speak to a particularly modern motif – the power of diversity. The diversity prediction theorem says that many models are better than single models; diversity can trump ability. As prosaic macro examples, Norway’s central bank has found that combining different forecasting models actually produces better inflation predictions. The Economic Modelling and Forecasting Group at Warwick Business School claims that weighting together the GDP and inflation forecasts of several models is a more robust procedure than relying on a single approach. The Bank of England is advocating interdisciplinary models that respect complexity, heterogeneity, networks, and heuristics.

At a more general level, the diversity prediction theorem implies that you should not be afraid to think and speak differently – you’re doing society a favour. More diversity is better than less; otherwise an undiversified “wisdom” leads to the badness of crowds; herds, manias and bubbles. A related issue is the benefit of humility: admitting ignorance is better than nursing an illusion of knowledge. Excess confidence can lead to bad decisions: the underestimation of true risk, the cultivation of complacency. In addition, do not overlook the value of simple rules of thumb that can work in the context of radical uncertainty. Better to be roughly right, than precisely wrong. Not a bad piece of advice, perhaps, for that final exam!

SPH
9 May 2019

In our session on exchange rates, we introduced the concept of interest rate parity. The basic idea is that efficient market forces will ultimately combine to produce a global benchmark for safe real interest rates. Safe usually means the short-term rates paid by State institutions such as the Fed, the US Treasury and their equivalents in other parts of the world. And short-term means just that – the yield paid on debt maturities that are often significantly less than one year. For such financial instruments, any interest rate divergences will prove temporary and associated with real exchange rate disequilibria.

Once we move beyond these short-term official rates it gets more complicated. Market rates, the longer-term interest rates – both official and private – that drive consumer and investment spending, typically involve risk. However, uncertainty is variable, not fixed, and depends on circumstances – not least the business cycle and mercurial expectations.

Moreover, beyond the short term, uncertainty is not confined to credit risk (where payment promises – if they exist – might not be honoured). Market rates will be buffeted by varying risk premia connected with defaults, market sentiment, inflation and economic prospects. As we learnt in session 7, asset prices – even of high credit quality US Treasury Bonds – can change simply because of fluctuations in policy or the inflation outlook. For most advanced economies, governments are hardly likely to default on their borrowing. But, US Treasuries and other government bonds can be highly volatile if investors alter their views about the likely path of short-term policy rates, perhaps because the inflation target seems less likely to be achieved. Even prospective moves in the regulatory environment or tax treatment of government debt could shift market prices, creating headaches for investors despite secure cash flow promises.

In Session 13, our penultimate teaching week, we explore the interactions of mobile capital, floating exchange rates, policy choices and international economic performance. As with our domestic AD-AS model we soon discover that fickle expectations play a key role. However, unlike goods and services, global financial asset prices are far from sticky. Valuations are highly sensitive to changes in beliefs. Moreover, such expectations are not always firmly rooted or classically rational. Bob Shiller’s article on potential reactions to the Fed’s widely-expected rate hike in December 2015 is highly recommended. His references to behavioural finance are worth noting with the theme of human psychology prominent in the literature on rational inattention. And take a look at the worked examples especially the topic of risk-on and risk-off dollar trading. Our session touches on the point that, when analysing shocks, it is important to assess whether that shock is expected to be temporary or permanent. Similarly key is whether markets see the “”shock” coming (an anticipated shock) or whether it comes completely out of the blue.

The November 2016 Presidential election heralded the adoption of both looser fiscal policy and tighter monetary policy. The standard prediction, as we confirm with the aid of a Mundell-Fleming model, is that real interest rates rise and the US dollar jumps sharply higher (creating expectations of future depreciation). Currency overshoots frequently occur and are in line with interest rate parity ideas. Given efficient arbitrage, high US interest rates can only co-exist with low European equivalents if the dollar is expected to weaken. What is gained on the yield roundabout is lost on exchange rate swings. That is exactly what interest parity means.

To digress, if only to underline earlier warnings about accounting pitfalls, do not necessarily assume that the much talked-about US corporate profit repatriations – prompted by the 2017 Tax Act – will necessarily boost the US$ through capital inflows. As noted here most of the corporate cash mountain is already in dollar-denominated assets!

In the wake of the 2016 US Presidential election, the dollar behaved pretty much in line with the standard model. After the initial post-Trump surge, the real broad effective US$ index fell by around 10% between end-2016 and end-2017. However, for a more rigorous examination of events, we turn to some empirical studies on policy divergence.

For example, IMF analysis confirms the importance of risk premia and interest rate differentials. A July 2016 study presents a plausible narrative explaining 2014-16 US$ strength in terms of risk premia and yield differentials. There is also evidence of a dollar safe haven effect in the context of heightened global risk.

A 2016 Fed study on international spillovers of monetary policy tackles another important theme. Specifically, changes in US monetary policy can significantly impact foreign economies.  Taking the example of GFC-related cuts in US interest rates, the analysis shows the quantitative importance of three distinct channels:

a) exchange rate: a softer dollar, reflecting lower interest rates, will boost US exports and so weaken foreign GDP
b) domestic demand: but, in the opposite direction, better US GDP performance – on the back of a weaker dollar – sucks in imports, so providing offsetting benefits to overseas producers
c) financial spillovers: lower US interest rates will pull down foreign asset yields so benefitting foreign GDP (although note BIS concerns about potentially greater risk-taking in emerging markets)

The Fed’s empirical work suggests that a) and b) net out. In other words, the overall effect of US monetary easing, represented by c), is GDP-positive for the world economy.

Of course, it is not always a one-way street as our feature video makes clear. Foreign developments can also independently impact the US. America is a large and powerful country, but we should never underestimate the importance of global networks and feedback effects. The dollar can change not just because of what happens in the US but also because of overseas shifts in asset prices and risk tolerance.

In quantifying these monetary spillover effects the Fed makes use of its SIGMA model, one of several that US officials use in framing interest rate and other policy decisions. As such, the empirical studies cited above are a useful prelude to our final session that focuses on large-scale macro models – both conventional DSGE models widely in use amongst central banks as well as increasingly popular Agent-Based Models (ABM).

Throughout the course we have gradually expanded our modelling expertise. But you will no doubt be aware that macro-analytical techniques faced extensive criticisms after the GFC. Are these models too pointy-headed, too remote from reality, to be of any use? Hopefully, I can persuade you that your sampling of these quantitative techniques has indeed been worthwhile.

SPH
2 May 2019

For the next couple of sessions we turn our attention to foreign currency and capital flows. There will be something for everyone: accounting revision, trade and financing riddles, geeky equations, financial arbitrage, politics and institutional design, model simulations. What’s not to like?

Our feature video takes up just one of the threads covered; specifically, whether structural flaws are tainting the Eurozone (euro area). The video focuses on one particular view that not all economists would agree with. Some, for example, would say that the region’s problems reflect bad policy choices rather than poor structure. However, it is hard to deny that Economic and Monetary Union is not really a union at all. It is a dog’s dinner that serves countries with very different economic structures, languages, legislatures, customs and regulations.

For sure, there is a huge common purpose – primarily to bind social and political ties so as to prevent a rerun of European wars that have plagued the region for many centuries. However, the project has too often required large, and painful, sacrifices that undermine essential co-operation and trust. The GFC delivered severe recessions (via required internal devaluations) in the so-called European “periphery”, creating bitterness and fuelling old rivalries between the North and South. For many economists this is no surprise since the Eurozone is hardly a convincing optimal currency area.

As the interviewee makes clear, and I agree, it is not the euro per se that is the problem. Rather, the flaw arises from the institutional setup of the Eurozone itself, principally revolving around the lack of policy flexibility.

The key problems areas are,

• inadequate provisions for national central banks to support liquidity-strained governments
• no sign of fiscal integration
• legal and social constraints on labour mobility
• insufficient supply of euro safe assets

Perhaps there is too much impatience. It takes a long time to move from old boundaries to new frontiers. The US in its infancy was arguably in a similar place to where EMU is now. But, almost twenty years on since the euro’s launch, there is precious little sign of governments engaging in supportive fiscal transfers. Full political union is unlikely and possibly unwarranted. That said, it would be a catastrophe if EMU itself were dissolved – especially in the midst of social and/or economic stress. The only way now is to push forward and reform: but so much more needs to be done on banking unions, fiscal co-ordination and structural integration if further EMU crises are to be contained.

On a more light-hearted note, another problem with the Eurozone is that few are actually clear as to what and where it is! Formally, the euro area consists of those Member States of the European Union that have adopted the euro as their currency.

It sounds straightforward but you do not have scratch far below the surface before confusion arises. Take Scandinavia…

• Finland is an EU member, uses the euro as its principal currency and so is a fully signed-up member of the euro area.
• Norway is not an EU member, retains its own currency and so is not in the euro area.
• Sweden is an EU member, retains its own currency and has not yet adopted the euro. That said, Sweden is obliged to use the euro once it fulfils the necessary conditions but, until then, it remains outside the euro area.
• Denmark is in a similar, but not identical, position as Sweden in that it is outside the euro area. Denmark is an EU member, retains its own currency but the krone shadows the euro. However, unlike Sweden, Denmark negotiated an opt-out from the euro and thus is not obliged to introduce it.

Are there European countries that are not EU members but who use the euro as their principal currency? Yes, the European microstates of Vatican City, Andorra, Monaco and San Marino all officially use the euro – with formal EU agreements – but are not part of the EU (hence, not part of the euro area). Kosovo and Montenegro both adopted the euro unilaterally in 2002 although, given the absence of an EU agreement, the currency is not de jure legal tender just de facto.

Then there is the issue of whether a country needs to be in Europe to be a euro user. Indeed, can you be outside Europe and yet still qualify as a euro area member?

Euro users such as the Canary Islands do not belong to Europe geographically but are an autonomous community of Spain and so qualify as part of the EU and the euro area. Similar considerations apply to the Azores and Madeira (in the Atlantic and belong to Portugal), Mayotte and Réunion (in the Indian Ocean and belong to France). French Guiana in South America uses the euro, qualifies as an EU member (via France) and is part of the euro area. But then Saint Pierre and Miquelon – just off the eastern coast of Canada – are formally part of France and use the euro but, as an “overseas collectivity” rather than “overseas departments”, do not qualify as members of the EU and thus are not formally part of the euro area.

So here’s a suggestion. Why not take a field trip to the Caribbean and determine the precise EU/euro area status of Guadeloupe, Martinique, Saint Martin and Saint Barthélemy? Research conclusions, please, on pretty postcards.

SPH
25 Apr 2019

I can’t believe that! said Alice.
Can’t you? the queen said in a pitying tone. Try again, draw a long breath, and shut your eyes.
Alice laughed. There’s no use trying, she said. One can’t believe impossible things.
I dare say you haven’t had much practice, said the queen.
When I was your age, I always did it for half an hour a day. Why, sometimes I’ve believed as many as six impossible things before breakfast.
Through the Looking Glass, Lewis Carroll (1871)

Here’s a possible final exam question…The Fed increases its nominal policy rate. Will inflation rise or fall?

So what’s your answer? Rise? Fall?

Hopefully, you now know me better than to expect either answer is correct in all circumstances. Our world of intermediate macroeconomics is too complex, too nuanced for easy binary outcomes. The “right” answer, though you would need to explain it, is that “it all depends”.

A few years ago the blogosphere was replete with economists getting their heads in a spin over Neo-Fisherianism. It was all a bit silly, but – like any good puzzle – it did raise some interesting issues about causality, dynamics and stability; issues that good macroeconomists need to care about. If you want to dive deeper try this, this and this.

Here’s the puzzle. Does higher inflation lead to a higher fed funds rate? Or does a higher fed funds rate lead to higher inflation? To put the question in a more contemporary context: did the Fed’s post-GFC hesitation in raising interest rates reduce or increase the risk of deflation?

The mainstream (liquidity) view is that higher interest rates, supported by temporarily lower monetary growth, would lead to lower inflation. Remember that the nominal interest rate is just the real interest rate plus expected inflation. If lower monetary growth is just temporary then there is no need for inflation expectations to change. This means that the higher nominal interest rate is reflected, one for one, in a higher real interest rate. That higher real rate temporarily dampens demand and thus actual inflation (relative to counterfactual trajectories).

But the Fisher (or neo-Fisherian) view says the opposite. Real interest rates are sticky since they are fundamentally driven by long-run forces of savings, productivity and global market conditions. Therefore, given that the nominal interest rate = “sticky” real rate + inflation expectations then higher nominal rates must largely be reflected in higher inflation expectations and thus higher actual inflation (with expectations of future monetary growth also increasing). If the Fisher view is right then, to avoid deflation, the Fed could have just raised interest rates without bothering with all that QE. Indeed, by not raising interest rates the central bank was actually undermining the impact of QE as a tool for lifting inflation expectations.

A little bit of thought suggests that the Fisher view puts too much reliance on long-run equilibria (expressed via identities) and pays insufficient attention to the dynamics of getting from A to B.

Comparing two different countries, both close to equilibrium, I would not be at all surprised if the country with higher inflation also had higher interest rates and vice versa.

However, if the country with high inflation decided it wanted permanently lower inflation then, as a practical matter, it seems very doubtful that cutting interest rates would do the trick. More likely, interest rates would need to rise a lot more first, reinforced by a recession to get the message embedded in expectations, before – ultimately – interest rates could fall to a lower level, commensurate with the desired lower inflation path. The Volcker disinflation of the 1980s provides a good example.

The debate is not new, as this 2001 piece from FRB Minneapolis illustrates. The key lessons to learn are that nothing can be taken for granted, that there is nothing new under the sun and that it’s good mental gymnastics to dream the impossible dream.

SPH
11 Apr 2019

In session 8 we explored a link between GDP spending and real interest rates called the IS curve.

It turned out that “IS” was a misnomer and would be better described as a WJ curve – the combination of output gaps and real interest rates where planned withdrawals W and planned injections J are (possibly only temporarily) in alignment.

In session 10 we look at another curve – often called the MP (monetary policy) or TR (Taylor Rule) curve. Like the IS curve it describes potential balancing acts of real interest rates and output gaps, but this time from the perspective of financial rather than non-financial products.

Unfortunately, like the IS curve, the name attached to our new line is also misleading. We are given the impression that the MP/TR curve is all about monetary policy and is primarily pushed around by central banks.

For sure, central banks play a role in guiding the economy’s interest rate/activity mix towards more friendly levels than what unsupervised markets might deliver. However, it is worth emphasising once again that real interest rates comprise three elements:

• a nominal policy rate (such as the fed funds rate)
• inflation expectations
• market risk premia

The central bank has most control over the first – the fed funds rate. Yet, even here, there can be exceptions. This became evident in the GFC when, for all practical purposes, the Fed could not reduce the rate below its Zero Lower Bound (ZLB). Moreover, with evidence that r-star is much lower than previously thought, this problem might well become more frequent going forward.

In contrast, inflation expectations and risk premia are subject to market vagaries and sentiment swings. Clearly these are not levers that a central bank can easily pull. Yet we should not be too disheartened. The GFC and its aftermath illustrated that the Fed (and Government) can gain traction in these areas if they work together, bolster confidence and enjoy credibility. The economy at large will then take on board that the State machinery will “do whatever it takes” to restore normality.

Such mind games require deploying the “dark arts” of central banking – forward guidance, communications, QE shock and awe. But to be credible, they also require governmental co-operation – supportive fiscal policy, new legal frameworks, recapitalisations. Central banks can do a lot more than just tinker with interest rates but they are not all-powerful.

So where does this leave us and our new-found MP/TR curve? Certainly we shall need to tread carefully. The mechanistic Taylor Rule, adopted by many a textbook, cannot be taken too seriously with its dependence – explicit or implicit – on imperfectly measured and/or dubious concepts such as output gaps, Phillips Curves and natural real interest rates.

And surely the Taylor Rule is too narrowly focused. As well as monetary stability, central banks are charged with the task of financial stability, seeking to ensure the integrity of the banking and payments system. The Taylor Rule has nothing to say about credit growth, lending standards, asset prices, capital adequacy – all vital if benign business and financial conditions are to co-exist. No surprise then there was some nervousness in 2017 about the potential appointment of John Taylor to the Fed.

More fundamentally, the benefits of inflation targeting in ZLB-infested waters have also come under scrutiny. Ben Bernanke’s suggestion about temporary price level targets looks interesting and has been considered before. The FRB San Francisco’s John Williams has also weighed in about the need for more policy space. Going further, more commentators are coming round to the view that we ask too much of monetary policy. Ideally, fiscal and structural policies are available to take a supportive role, provided – as we learnt in Session 9 – that there is sufficient debt space to do so.

SPH
4 Apr 2019

In the early part of our course we explored some of the structural problems challenging policymakers. Specifically, we identified evidence of stagnation in productivity growth and thus a slowing in the growth of living standards. Not unrelated, we have seen clear signs that the “normal” real interest rate, r-star, has fallen in recent decades.

In our sessions dealing with business cycles, the implications of a low r-star for demand management will become clearer. For any given inflation target, a lower “normal” real interest rate must mean that a central bank’s “normal” nominal interest rate must also be lower. In the US’s case, for instance, our session 10 exercise in Fed Watching (using dot plots) will suggest that the FOMC is indicating 3% as the new normal for the fed funds rate rather than 4% as was assumed pre-GFC.

This downgrading of normal policy rates is important since it suggests that central banks will have less headroom than in the past should we be afflicted by another recession which necessitates aggressive interest rate cuts. The effective lower bound, not significantly different from zero, is much closer than it was over a decade ago.

So with signs that monetary policy is more constrained – at least in its conventional interest rate setting form – it comes as no surprise that fiscal policy will probably bear more of the burden of demand management in future business cycles. Governments, as well as central banks, will need to be more proactive.

But fiscal policy also has its problems.

• Automatic stabilisers are not that large and discretionary shifts in tax & spend programs can take time – too much time – to plan, agree and implement in modern democracies. In addition, even when fully implemented, fiscal policy may fail to gain to gain traction. 
• Multipliers, even if they are positive in the short run, often fade to nothing within a short space of time.
• As we discussed in session 8, crowding out is not always a problem – especially in large recessions – but the potential for failure in the transmission mechanism cannot be denied.

In session 9 we explore in more detail the challenges that arise when fiscal policy is more actively used to cushion a weak economy. In particular, after becoming more familiar with budget accounting measures, we are going to address the question of long-run fiscal sustainability.

Unless matched by productive assets, high debt can hamper growth, diverting resource from more productive uses and so undermining the long-run tax base. High debt also means high debt payments (our INT of T = TX – TR – INT fame from early accounting sessions). But high debt payments mean higher budget deficits which mean more debt in future. If you’re thinking “this sounds like a doom loop” – well, you’re right!

If the economy is stagnating, and thus not producing much growth in tax revenues, then interest payments will feed a vicious cycle leading to ever increasing debt. But ever increasing debt will get investors twitchy who will then sell that country’s debt – forcing interest rates even higher! Like so many financial cycles, we get into a nasty, self-fulfilling prophecy of doom. Fiscally weakened governments, recessionary economic conditions and failing banks – a toxic brew indeed.

Following the GFC, when both central banks and governments pulled out all the stops to prevent a socio-economic collapse, many countries have been left with a huge public debt legacy. As the introductory video makes clear, governments are striving to contain this debt overhang by running underlying budget surpluses as well addressing some of the structural barriers to higher growth (and thus a stronger base for tax revenue).

The bottom line is that fiscal largesse – perhaps launched with noble, anti-depression motivations – can exacerbate problems rather than solve them.

The analysis contained in the video accompanied the IMF’s April 2013 Fiscal Monitor. The narrative focused on 10 major countries that accounted for the bulk of global public debt. The list included the US, Japan and several Europeans. So how are they getting on now?

For an update let’s look at the IMF’s latest projections for government debt (as a % of GDP) for 2020 and compare that forecast with the outturn for 2013, when the IMF’s analysis was compiled. One country appears to be back on the straight and narrow. Ireland seems set to reduce its debt ratio to around 60% from 120%. Portugal is also making modest progress although its debt ratio is projected to remain significantly above 100% in 2020. However, all the rest have either seen their debt ratios stabilise at high levels or, in some cases, are even set to increase.

The US is a case in point. The legislative changes in the 2017 Tax Act plus additional measures in early 2018 will set America on a much more fiscally expansive path.

The Congressional Budget Office’s April 2018 assessment makes for sober reading…

“federal debt is projected to be on a steadily rising trajectory throughout the coming decade. Debt held by the public, which has doubled in the past 10 years as a percentage of gross domestic product (GDP), approaches 100 percent of GDP by 2028 in CBO’s projections. That amount is far greater than the debt in any year since just after World War II. Moreover, if lawmakers changed current law to maintain certain current policies — preventing a significant increase in individual income taxes in 2026 and drops in funding for defense and nondefense discretionary programs in 2020, for example — the result would be even larger increases in debt.”

“Over the 2021–2028 period, projected deficits average 4.9 percent of GDP; the only time since World War II when the average deficit has been so large over so many years was after the 2007–2009 recession.”

Part of our session will explore what the projections mean for US fiscal sustainability (if time permits, the outlooks for Brazil and Russia will also come under scrutiny). Other than eating humble pie, reversing the tax cuts and spending programs, there are no easy fixes for the problems we uncover.

• Selling the family silver? …buys some time but asset stripping is, itself, unsustainable
• Resource bounty? …unlikely that shale is enough and then there’s that dreaded resource curse
• Inflate the debt away?… quite possibly, it’s been done before!
• Financial repression?… capping interest rates is a throwback to WW2 and its aftermath, again not a new idea but much harder to implement in today’s market environment
• Rebound in productivity growth? …ok, now you’re talking. Good luck with that, but at least it underlines the key point that fiscal sustainability is more about supply-side policy than occasional budget squeezes. Moreover, supply-side policy needs to pay close attention to the financial sector; poor bank capitalisation, inadequate liquidity, weak regulation will only intensify fiscal sustainability problems. As the GFC debacle proved, private banking problems quickly morph into massive public debt headaches. If you have great policies with great institutions nurturing great ideas then great results follow. Fiscal space can be created by additional public spending in carefully chosen infrastructure and other projects. Crowding in can happen and it is certainly worth trying. But , if it were that easy, you wouldn’t have a fiscal sustainability problem!

Of course, the US enjoys an “exorbitant privilege” in that it has a captive audience as regards creditors. America’s perceived safe haven status, also reflected in the primacy of the US$ in international finance, means that it can preside over widening deficits and mounting debt burdens without necessarily suffering a crisis of credibility. For sure, it is doubtful that the dollar and US Treasury bonds are about to collapse any time soon. But, as history and playground antics teach us, you can only stretch the elastic so far before it snaps back in your face!

SPH
28 Mar 2019

Models are a key tool in macroeconomics and we need to invest time in learning the key tricks, checking that,

• we know the difference between exogenous and endogenous variables
• the number of equations equals the number of endogenous variables to solve for
• a solution actually exists
• where models are dynamic, stability is feasible

Models are useful. They help us to focus on key issues at hand, removing unnecessary detail and sometimes revealing conclusions that were not immediately obvious. But models can also lead us astray if we are not careful. Key pitfalls include

• catching partial derivative disease; assuming all other things equal (ceteris paribus) when, in real life, they are not
• thinking that the whole is simply the sum of the parts; not always so as we move from micro motivations to macro consequences, with the Paradox of Thrift a great example
• believing that the model will work in all circumstances; parameters and behaviour often change, for example, when an economy moves from boom to bust
• assuming that all driving forces are objective, measurable variables; our case studies will touch on the the power of expectations – how beliefs about the future shape the present and how uncertainty (the degree of comfort with the expectations formed) can play an additional role in spending decisions
• supposing that governments (and central banks) invariably get matters under control; it is not always obvious what fiscal and monetary levers to pull, nor are the impacts easy to predict given limited information about the future and the vagaries of human behaviour 

The standard workhorse model of domestic business cycles comprises three equations. One is the Phillips Curve – the relationship between the output gap and inflation that we tackled in Session 6. Another is the TR/MP curve that examines one relationship between real interest rates and expenditure, operating through monetary policy and financial markets. That we shall leave to Session 10 where we draw on material from our Money & Finance session, recognising that real interest rates are not simply an outcome of monetary policy but also inflation expectations and risk premia.

For session 8 we focus on another relationship between real interest rates and expenditure – called the IS curve – that operates through non-financial goods and services markets, notably consumption, investment and government spending. We shall follow convention, and the textbook, in calling that relationship an IS curve even though the name often confuses and misleads. Strictly speaking it is the combination of real interest rates and the output gap that ensures planned withdrawals (W) equal planned injections (J). As you know from our accounting identities, W=J does not require I=S so the properties of the IS line would be clearer if we all called it the WJ line!

In constructing the IS curve and examining its slope and shift factors we focus on consumption (C), investment (I) and government spending (G). Net exports are dealt with only briefly since we shall delay discussion of external trade and cross-border capital flows to Sessions 12 and 13.

The Jones textbook (notably chapters 16 and 17) devotes a lot of space to the micro foundations of domestic private sector spending,  so we do not need to repeat that in the lecture. In any case, the empirical evidence supporting micro/neoclassical models is somewhat patchy.

• For example, the so-called Euler Equation (Jones, pp 452-455) – derived from intertemporal models of utility-maximising consumption models – appears not to fit the facts. The Euler Equation predicts that, for any degree of impatience, higher real interest rates are associated with stronger planned consumption growth – in other words, present consumption is restrained in favour of more consumption in the future. In practice, it seems that the opposite is the case. This could be a mirage (the statistical problems of separating out causes and effects are notoriously hard) but it could reveal more fundamental problems such as the absence of assumed perfect financial markets and, even more damning, the wholly misleading use of a representative individual to reflect decisions by a heterogenous mix of consumers who build habits and sometimes “act dumb”. Even if individuals do act rationally, outcomes can still end up in a collectively irrational “bad equilibrium”.
• As for investment, we examine evidence that accelerator (output gap) influences, together with expectations and uncertainty, appear much more important than variations in posted interest rates. The past affects the present but, arguably, the future is even more important; and no-one knows for sure what is going to happen. Hence, a huge role for sentiment, confidence and speculation – fickle stuff that is hard to capture or model. Such Keynesian-style thinking is nonetheless well suited to exploring hysteresis (cycle-trend interactions) and the stagnation themes revealed in Session 4. Indeed, problems of self-fulfilling prophecies – and thus the possibility of persistent deviations from the full-employment steady state  – underpin the rationale of contra-cyclical fiscal and monetary policy. Moreover, the policy instruments can be extended from classic “hard” tools (spending, taxes, interest rates) to “soft” brushes (nudges, guidance, artful communications).
• Government spending is another focus of Session 8. This leads us into a discussion of the so-called “crowding out” phenomenon, automatic stabilisers and the concept of the Keynesian expenditure multiplier (topics that shall be examined more deeply in Session 9). Again, we learn that elementary textbook “rules” are often invalid – the real world does not easily fit into simple theoretical boxes. Sometimes government action works as intended, sometimes not; the state of the economy and the degree to which private sector behaviour is influenced are key variables that can be tricky to pin down. “Partial derivative disease” is particularly dangerous; assuming other things equal (ceteris paribus) is often misleading, sometimes just plain wrong. On Planet Earth, “fixed” rarely happens.

A key conclusion from our session is that there can be no decisive right answers about the impact of government spending on the economy. You should dip further into that debate but not get discouraged by the enormously wide range of views on offer. Your opinion is as good as anyone else’s but the important point is that you should see where the arguments are coming from and what assumptions are most in need of further investigation.

Macroeconomics is full of such belief-challenging controversies and intellectual fisticuffs. It is what makes the subject so interesting and relevant. As Banksy said about his own trade, “People say graffiti is ugly, irresponsible and childish… but that’s only if it’s done properly.”

SPH
21 Mar 2019

Money is a special product in that it performs several must-have functions. Yet money comes in different shapes and sizes – physical, digital and in various denominations. Essentially money is a promise, a debt. We no longer inhabit a world of commodity-backed money, ye olde gold standard. Money is what is generally accepted as money and the principal suppliers are private sector banks that have licences to “print” deposits, typically as counterparts to loans. A big helping hand that gives money its moneyness is, of course, official blessing. Namely, State-backed legitimacy and the generous provision of government/central bank support for the private banking system.

So, for fiat money,

• how much is the promise worth?
• what, exactly, is the price of money?
• how will money’s value change if the promise is suspect?

For this exercise, let’s focus on money in its “top quality” format, that is a liability of a government, or more typically, a central bank. This “top quality” money – the best that money can buy – is called the monetary base or high-powered money and FRED is at hand with data. Now let’s illustrate, with the help of simple demand-supply diagrams, the four prices of money, namely

• the interest rate price
• the foreign exchange price
• the goods price (inverse of the CPI), and,
• the par price (a $ is always a $, right? Wrong!)

Interest rate price. A price is an opportunity cost and the most frequently quoted price for money is an interest rate, reflecting the fact that money (as a demand deposit or cash) typically earns no yield. By having wealth in money format, you are forgoing the opportunity of earning interest on, say, a bill or bond. Using a standard demand and supply diagram we can illustrate this “price” and how it might change, if, for example, the Fed tightened policy by raising interest rates (necessarily being supported by a reduction in the monetary base).

Forex price. An alternative to holding a dollar is to hold another currency, say, sterling. Say the Fed supports a decision to slash interest rates by pumping up money supply, perhaps via Quantitative Easing. Other things equal, the price of a dollar – in sterling terms – will go down. You get less sterling for a dollar. Note you need to be careful as to how you express the exchange rate. Typically, “cable” – the nickname for the dollar-sterling exchange rate – is expressed as $ per £. That’s not going to work in our diagram since we are interested in the price of a dollar, NOT the price of a pound! More of this in sessions 12 and 13.

Goods price. Instead of holding value as $ money you could buy goods and services – we’ll use the catch-all term “Widget” for products in general. Our diagram this time shows a demand-side shift, a weakening of demand for money perhaps because people are worrying that product prices will go up. Buy now, before stuff gets more expensive! The effect is to weaken the price of money (in Widget terms). Expectations of inflation have actually become a self-fulfilling prophesy. We’ll be returning to that issue before too long.

Par. Remember that our focus here is “top quality” money. Cash, such as Federal Reserve notes, falls into this category as do electronic deposits at the central bank (usually only available to a select group of banks).  FRED can show you that high-powered money increased sharply during the Great Financial Crisis, representing a surge of demand for safe, as opposed to risky, money. We illustrate this surge in the relevant diagram below. In 2008 some types of money – such as funds placed in Money Market Mutual Funds (MMMF) – suddenly “broke the buck“. For a while, an MMMF dollar was worth only 97c of a “proper” dollar (eg cash). Par was broken, a sure sign that the financial system was close to meltdown. Little wonder that the public authorities acted swiftly and aggressively to avoid the apocalypse. Restoring par, the litmus test of a functional banking system, required the authorities both to boost “top quality” money supply as well as contain the loss of confidence in substitute money (sometimes called quasi-money or shadow money). The GFC reminded us of a very important historical lesson: not all moneys are born equal.

SPH
21 Mar 2019