Interest Rates and Debt Ratios

Paul Krugman links us to a fascinating new report by the BOE (.pdf) which also presents some really really long time-series data on a hotly discussed issue over the past years, but also very much relevant for some of the discussions we’re having on this forum: the ability of governments to borrow and the limits to this borrowing. Below the relationship between long-term bond yields and debt-to-GDP ratios of the UK ranging all the way back to the 1700s.

The whole issue is of course strongly related to e.g. the 90% threshold level of debt-to-GDP ratio found (or not) after which economies abruptly start dying (again, or not) in the now infamous Reinhart-Rogoff paper (.pdf). Christoph, in his last guest post, also writes that “Empirical articles show that the higher the deficits and debts are, the higher is the probability of a country to experience a “sudden stop” of capital inflows”. As he points out in the comments, causality and correlation are indeed tricky to disentangle, yet the point seems to stand that a high debt-to-gdp ratio makes a country inherently a more risky investment. I, for one, am not sure why this should be the case. There are many things that might make a country a risky investment, and also many reasons that might lead to “sudden stops” in the willingness of investors to finance a country’s deficit. But, and as counter-intuitive as this might sound, the level of debt-to-GDP simply does not seem to be one of them, as the graph above but also the eperience of e.g. Spain in the current crisis and Japan over the past couple of decades, to name just three of the most obvious examples, show. This supposedly existent causal relationship – or indeed any meaningful relation at all – between debt levels and the ability of a country to finance itself seems not only wrong but utterly destructive. Spain (and Europe in general) has many huge problems it needs to tackle, but its debt level is not one of them (Greece, of course, is a different story).

As a final note, the authors in the paper note that “Increases in the public debt ratio resulting from military spending were often associated with increased government bond yields”. The most obvious exception to that is the second world war. The authors hint that the rise of interest rates in many past episodes of war “mainly reflected fluctuations in the fortunes of war”, but could this also be interpreted as representing the difference of fiscal spending that crowds out and that which crowds in? I don’t really know much about the other historical episodes but the spending undertaken that got us out of the Great Depression clearly would be a case of the latter, explaining why interest rates fell.

The Shortcomings of the Friedman Rule

My recent background reading on all things monetary economics has often led me to stumble on what is generally dubbed the Friedman rule for optimal monetary policy. As the name already implies, it is the result at which Friedman arrived when trying to derive how a central bank should set its nominal interest rate in order to achieve the best, most socially desirable outcome. The logic behind it is simple. Interestingly enough, even Friedman assumed that money was indeed not neutral, essentially for reasons similar to the mundell-Tobin effect: money always pays 0% nominal interest rates. Yet, people still both want and need to hold money, so the optimal policy in this world is one were the opportunity costs of holding cash is minimized, which means setting the nominal interest rate in the economy also to zero. This implies that the optimal inflation rate is should be negative – negative the real interest rate, to be precise. This finding seems odd, and is obviously very different from what central banks do in practice.

First of all, holding cash does indeed bring higher opportunity costs if the nominal interest rate set by the central bank is positive. Yet, of course, holding money also has benefits, the most important of which is liquidity. As such, it would seem that these benefits, that no other financial asset offers in the same degree, should seem to alter the optimality rule. Setting nominal interest rates to zero in this setting would seem to “unfairly” make money more attractive than comparable assets, and present a distortion in and of itself. The only way to argue that these benefits should not be taken into consideration would be if these private benefits were of the same magnitude as the social benefits they bring, which might but also might not be the case. Also, some have argued that inflation should be positive since it can be the only way to tax things that we would want to tax but often find hard to do (like tax evasion, for instance), but also for a whole slew of other reasons.

But, and more importantly, this “friction” from the demand of fiat money is the only friction entailed in the model. Yet probably one of the most vital things that Keynesianism taught us is that prices are sticky, particularly when it comes to the downside. This assymetry also means that the optimal inflation rate is not zero, but positive to take into consideration the natural “variance” of inflation. There is, of course, no way that a policy that calls for considerable negative inflation rates can be optimal in the real world, and even though the inflationary 70s did represent a major defeat of the type of Keynesianism found both in practice and in theory at the time, throwing all of it overboard, as evidently done by Friedman and others in coming up with this not-so-optimal monetary policy rule was a horrible idea that thankfully was never implemented. To be fair, even new Keynesian models find that the optimal inflation rate is considerably lower than the one used in practice, which is puzzling, but at least they include many of the real world issues we face to come to the conclusion.

Can Redistribution Get Us Out of The Recession?

Another Guest Post by Max Gödl, enjoy!

One argument I frequently hear in discussions on macro policy is that income inequality is a big drag on our economy right now. The reason is that rich folks save a larger fraction of their income than poor folks. Hence redistributing income from the top to the bottom increases aggregate spending which “grows the economy”. Let’s do it!

My response to that is: woah, woah, woah!

First of all, when presented in this way the argument is a non sequitur. It’s pretty clear that the rich have a higher average propensity to save than the poor. But that does not imply that their marginal propensity to save is higher, too. And it’s the latter that counts: Redistribution from rich to poor increases aggregate consumption only if the poor spend a larger fraction out of additional income than the rich. (Nerds, think Keynesian consumption function: C = a + bY. C/Y decreases with income, but dC/dY doesn’t!)

Now it turns out that the evidence on the marginal propensities to save of different income groups is surprisingly inconclusive. It has been known for ages that the positive correlation between current income and saving rates typically found in cross-sectional data doesn’t tell us anything about the relationship between saving rates and permanent income. There is a pretty large (but pretty old) literature, beginning with Milton Friedman’s classic 1957 work, showing that the MPS does not vary systematically with permanent income. So if income is measured over longer periods, the rich seem to save the same fraction out of additional income as the poor.

A more recent study by Dynan, Skinner and Zeldes (pdf) produces evidence that the rich actually do have a somewhat higher MPS than the poor. According to one of their estimates, the MPS of the bottom quintile of the income distribution is 16 percentage points lower than the MPS of the top quintile. And that’s their most generous estimate! Dynan et al. use U.S. data and I couldn’t find a similar study for Europe. Nevertheless, let’s take this number and think this through. The share of the top quintile in aggregate income is roughly 40 percent in the European Union, while the share of the bottom quintile is below 10 percent. If we would take 10 percentage points away from the top and give it to the bottom, aggregate consumption would increase by only 1.6 percent of aggregate income. So even a massive redistribution would only have a modest expansionary effect.

Finally, the expansionary redistribution hypothesis has an awkward implication. If shifting income from top to bottom increases aggregate spending, doing the opposite must decrease it. Do those who want to tax the rich and feed the poor to stimulate the economy in recessions also want to tax the poor and feed the rich during the boom years when the economy is overheating? I very much doubt it. But it would seem to be the logical implication of their theory.

There may be a good case for higher taxes on the rich and higher transfers to the poor. But we shouldn’t expect redistribution to get out of the recession.

Alan Greenspan on The Daily Show

First of all, Jon Stewart is awesome. I have no idea how I could have gone so long without ever stating this here. If you are even remotely interested in American politics and enjoy good comedy, The Daily Show is as good as it gets.

If you’re here just for the economics, you can always just skip the first part and scroll right to the interview, which starts at around 14:00. Clearly, The Daily Show is not the platform for overly wonkish, in-depth policy discussion, but still very worthwhile. From what I’ve read on his new book, the degree to which Greenspan has changed his views since the financial crisis seems to be fairly limited, but no real comment on that for now.

PS: It seems I cannot embed the second part of the interview. Here’s the link to the Daily Show directly.

Some More on Targets and Inequality

Caution: wandering mind and thoughts in process of clarification.







On Growth Rates and Growing Levels

Monetary economics, as any other academic field, requires basic agreement on a limited but vital set of definitions in order to be able to debate in a meaningful way. For central banks, two important terms are the distinction between monetary policy targets and monetary policy instruments. At the risk of stating the obvious, the targets of a central bank is generally a fairly easily verifiable variable that is supposed to be influenced by the central bank in the hope of achieving good economic outcomes. In most cases this target currently is the inflation rate, but other might also be nominal GDP, a monetary aggregate or even an exchange rate. The influencing of this target involves adjustments to the instruments of monetary policy, which include things like open market operations, the discount rate and reserve requirements.

In the choice of the target it is also of vital importance to specify whether we are talking about a growth rate target or a (growing) level target. Our current system works using growth rates: no matter what happened in the past, the central bank tries to get inflation rate back to its target of generally 2%. This is a sort of let-bygones-be-bygones policy. A growing level target, such as the one championed by Scott Sumners with NGDP level targeting, on the other hand, tries to get the target variable back on track to reach its pre-crisis trend level, meaning in the case of a depression would require considerably stronger monetary easing than a mere growth rate target. A mix of sloppyness and lack of clarity on my side has sometimes led me to muddle the two together in the past. “Basically, it is a central bank’s role to stabilize NGDP growth, and it should do whatever it takes to do so” is clearly a bit ambiguous, so let me try and set some of that straight by shortly going into why this difference is important

McCallum (.pdf) for one, in a survey of the literature on the topic, seems to favor a growth rate target. He stresses that, again by essentially ignoring the past, such a target essentially introduces a kind of random walk into the time series, and theoretically allows for the target variable to wander arbitrarily far away from any predetermined path. But then again, it wasn’t the point to begin with to follow any predetermined path. A growing levels target, on the other hand, by often requiring a more activist monetary policy in response to shocks, would tend to increase cyclical swings in demand, potentially increasing the variability (note: not the variance! I am not quite sure how accurate the term “variability” is, but I’m sticking to McCallum’s definition here) of variables such as real GDP in the process. In his words, “variability in output or other real aggregative variables is probably more costly in terms of human welfare than is an equal amount of variability in the price level about a constant or slowly-growing path”. Also, if what the economy just experienced turned out to be a permanent shock, stubbornly clinging to a predetermined growing level path would clearly be counterproductive.

The argument concerning the permanence of shocks is well-taken and important. As he notes, “although it is not entirely clear that fully permanent shocks are predominant, most time-series analysis seems to suggest the effects of shocks are typically quite long lasting – indeed, are virtually indistinguishable from permanent”. As far as I can tell this depends not so much on the nature of the shocks analyzed but rather on the policy response to that shock. If a central bank has a growth rate target, and thus does not try to force the economy back to its pre-crisis growth path, the obvious result would be to make a shock permanent even if it actually was not. How permanent a shock is would therefore seem to depend in practice, more often than not, on the adequacy of policy response to that shock rather than on the shock itself. Also, just because an economy experienced a “permanent” shock in one area doesn’t mean that with adequate policy another area of the economy can take up the slack. The bursting of a housing bubble might well be a permanent shock to the housing market, yet there is no reason it has to be a permanent shock to the economy as a whole.

And what the variability argument is concerned, I would also not agree that a lower but more stable level of economic activity, as we are currently experiencing, would be more preferable to a few years of increased variability after which we can then return to operating at full capacity. Sure, variability is a issue, but so is demand shortfall. When increased variability comes from an upswing it would seem like the lesser of the two evils. Further, the mere announcement that the level and not just the growth rate would be targeted implicitly states, as already mentioned, that a central bank is aiming to be more activist, which in an of itself might reduce the magnitude of downswings and thus variability through its effect on expectations. In any case it would seem sensible to, as generally with monetary policy, err on the side of doing too much rather than doing too little, and as such a growing levels target seems to be the superior choice.