Archive for the ‘Theory’ Category

The Limits to Trusting the Robots

October 20, 2017 Leave a comment

After another day on Thursday of stocks starting to look mildly tired – but only mildly – only to rally back to a new closing high, it hardly seems unusual any more. I have to keep pinching myself, reminding myself that this is historically abnormal. Actually, very abnormal. If the S&P 500 Total Return Index ends this month with a gain, it will be the second time in history that has happened. The other time was in 1936, as stocks bounced back from a deep bear market (at the end of those 12 months, in March 1936, stocks were still 54% off the 1929 highs). A rally this month would also mean that stocks have gained for 19 out of the last 20 months, the longest streak with just one miss since…1936 again.

But we aren’t rebounding from ‘oversold.’ This seems to be a different situation.

What is going on is confounding the wise and the foolish alike. Every dip is bought; the measures of market constancy (noted above, for example) are at all-time highs and the measures of market volatility such as the VIX are at all-time lows. It is de rigeur at this point to sneer “what could go wrong?” and you may assume I have indeed so sneered. But I also am curious about whether there is some kind of feedback loop at work that could cause this to go on far longer than it “should.”

To be sure, it shouldn’t. By many measures, equities are at or near all time measures of richness. The ones that are not at all-time highs are still in the top decile. Buying equities (or for that matter, bonds) at these levels ought to be a recipe for a capitalistic disaster. And yet, value guys are getting carried out left and right.

Does the elimination (with extreme prejudice) of value traders have any implications?

There has been lots of research about market composition: models, for example, that examine how “noise” and “signal” traders come together to create markets that exhibit the sorts of characteristics that normal markets do. Studies of what proportion of “speculators” you need, compared to “hedgers,” to make markets efficient or to cause them to have bubbles form.

So my question is, what if the combination of “buy the dip” micro-time-frame value guys, combine with the “risk parity” guys, represents a stable system?

Suppose equity volatility starts to rise. Then the risk-parity guys will start to sell equities, which will push prices lower and tend to push volatility higher. But then the short-term value guys step in to ‘buy the dip.’ To be clear, these are not traditional value investors, but rather more like the “speculators” in the hedger/speculator formulation of the market. These are people who buy something that has gone down, because it has gone down and is therefore cheaper, as opposed to the people who sell something that has gone down, because the fact that it has gone down means that it is more likely to go down further. In options-land, the folks buying the dip are pursuing a short-volatility strategy while the folks selling are pursuing a long-volatility strategy.[1]

Once the market has been stabilized by the buy-the-dip folks, who might be for example hedging a long options position (say, volatility arbitrage guys who are long actual options and short the VIX), then volatility starts to decline again, bringing the risk-parity guys back into equities and, along with the indexed long-only money that is seeking beta regardless of price, pushing the market higher. Whereupon the buy-the-dip guys get out with their scalped profit but leaving prices higher, and volatility lower, than it started (this last condition is necessary because otherwise it ends up being a zero-sum game. If prices keep going higher and implied volatility lower, it need not be zero-sum, which means both sides are being rewarded, which means that we would see more and more risk-parity guys – which we do – and more and more delta-hedging-buy-the-dip guys – which we do).

Obviously this sort of thing happens. My question though is, what if these different activities tend to offset in a convergent rather than divergent way, so that the system is stable? If this is what is happening then traditional value has no meaning, and equities can ascend arbitrary heights of valuation and implied volatility can decline arbitrarily low.

Options traders see this sort of stability in micro all the time. If there is lots of open interest in options around, say, the 110 strike on the bond contract, and the Street (or, more generally, the sophisticated and leveraged delta-hedgers) is long those options, then what tends to happen is that if the bond contract happens to be near 110 when expiry nears it will often oscillate around that strike in ever-declining swings. If I am long 110 straddles and the market rallies to 110-04, suddenly because of my gamma position I find myself long the market since my calls are in the money and my puts are not. If I sell my delta at 110-04, then I have locked in a small profit that helps to offset the large time decay that is going to make my options lose all of their remaining time value in a short while.[2] So, if the active traders are all long options at this strike, what happens is that when the bond goes to 110-04, all of the active folks sell to try and scalp their time decay, pushing the bond back down. When it goes to 99-28, they all buy. Then, the next time up, the bond gets to 110-03 and the folks who missed delta-hedging the last time say “okay, this time I will get this hedge off” and sell, so the oscillation is smaller. Sometimes it gets really hard to have any chance of covering time decay at all because this process results in the market stabilizing right at 110-00 right up until expiration. And that stabilization happens because of the traders hedging long-volatility positions in a low-volatility environment.

But for the options trader, that process has an end – options expiration. In the market process I am describing where risk-parity flows are being offset by buy-the-dip traders…is there an end, or can that process continue ad infinitum or at least, “much longer than you think it can?”

Spoiler alert: it already has continued much longer than I thought it could.

There is, however, a limit. These oscillations have to reach some de minimus level or it isn’t worth it to the buy-the-dip guys to buy the dip, and it isn’t worth reallocation of risk-parity strategies. This level is much lower now than it has been in the past, thanks to the spread of automated trading systems (i.e., robots) that make the delta-hedging process (or its analog in this system) so efficient that it requires less actual volatility to be profitable. But there is a limit. And the limit is reach two ways, in fact, because the minimum oscillation needed is a function of the capital to be deployed in the hedging process. I can hedge a 1-lot with a 2 penny oscillation in a stock. But I can’t get in and out of a million shares that way. So, as the amount of capital deployed in these strategies goes up, it actually raises the potential floor for volatility, below which these strategies aren’t profitable (at least in the long run). However, there could still be an equilibrium in which the capital deployed in these strategies, the volatility, and the market drift are all balanced, and that equilibrium could well be at still-lower volatility and still-higher market prices and still-larger allocations to risk-parity etc.

It seems like a good question to ask, the day after the 30th anniversary of the first time that the robots went crazy, “how does this stable system break down?” And, as a related question, “is the system self-stabilizing when perturbed, or does it de-stabilize?”

Some systems are self-stabilizing with small perturbations and destabilizing with larger perturbations. Think of a marble rolling around in a bowl. A small push up the side of the bowl will result in the marble eventually returning to the bottom of the bowl; a large push will result in the marble leaving the bowl entirely. I think we are in that sort of system. We have seen mild events, such as the shock of Brexit or Trump’s electoral victory, result in mild volatility that eventually dampened and left stocks at a higher level. I wonder if, as more money is employed in risk parity, the same size perturbation might eventually be divergent – as volatility rises, risk parity sells, and if the amount of dip-buyers is too small relative to the risk parity sellers, then the dip-buyers don’t stabilize the rout and eventually become sellers themselves.

If that’s the secret…if it’s the ratio of risk-parity money to dip-buyer money that matters in order to keep this a stable, symbiotic relationship, then there are two ways that the system can lose stability.

The first is that risk parity strategies can attract too much money. Risk parity is a liquidity-consumer, as they tend to be sellers when volatility is rising and buyers when volatility is falling. Moreover, they tend to be sellers of all assets when correlations are rising, and buyers of all assets when correlations are falling. And while total risk-parity fund flows are hard to track, there is little doubt that money is flowing to these strategies. For example one such fund, the Columbia Adaptive Risk Allocation Fund (CRAZX), has seen fairly dramatic increases in total assets over the last year or so (see chart, source Bloomberg. Hat tip to Peter Tchir whose Forbes article in May suggested this metric).

The second way that ratio can lose stability is that the money allocated to buy-the-dip strategies declines. This is even harder to track, but I suspect it is related to two things: the frequency and size of reasonable dips to buy, and the value of buying the dip (if you buy the dip, and the market keeps going down, then you probably don’t think you did well). Here are two charts, with the data sourced from Bloomberg (Enduring Intellectual Properties calculations).

The former chart suggests that dip-buyers may be getting bored as there are fewer dips to buy (90% of the time over the last 180 days, the S&P 500 has been within 2% of its high). The latter chart suggests that the return to buying the dip has been low recently, but in general has been reasonably stable. This is essentially a measure of realized volatility. In principle, though, forward expectations about the range should be highly correlated to current implied volatility so the low level of the VIX implies that buying the dip shouldn’t give a large return to the upside. So in this last chart, I am trying to combine these two items into one index to give an overall view of the attractiveness of dip buying. This is the VIX, minus the 10th percentile of dips to buy.

I don’t know if this number by itself means a whole lot, but it does seem generally correct: the combination of fewer dips and lower volatility means dip-buying should become less popular.

But if dip-buying becomes less popular, and risk-parity implies more selling on dips…well, that is how you can get instability.

[1] This is not inconsistent with how risk parity is described in this excellent paper by Artemis Capital Management (h/t JN) – risk parity itself is a short volatility strategy; to hedge the delta of a risk parity strategy you sell when markets are going down and buy when markets are going up, replicating a synthetic long volatility position to offset.

[2] If this is making your eyes glaze over, skip ahead. It’s hard to explain this dynamic briefly unless I assume some level of options knowledge in the reader. But I know many of my readers don’t have that requisite knowledge. For those who do, I think this may resonate however so I’m plunging forward.


The Mystery of Why There’s A Mystery

October 10, 2017 Leave a comment

We have an interesting week ahead, at least for an inflation guy.

Of course, the CPI statistics (released this Friday) are always interesting but with all of the chatter about the “mystery” of inflation, it should draw more than the usual level of attention. That’s especially true since the mystery will cease to be a mystery fairly soon as even flawed indicators of inflation’s central tendency, such as the core CPI, turn back higher. This is not particularly good news for many pundits, who have declared the mystery to be solved with some explanation that implies inflation will stay low.

  • “Amazon effect”
  • Globalization
  • “competition”
  • Etc

The first of these I have addressed previously back in June (“The Internet Has Not Killed, and Will Not Kill, Inflation”). The second is a real effect, but it is a real effect whose effect peaked in the early 1990s and has been waning since then. I wrote something in our quarterly in Q4 last year, which is partly summarized here.

The “competition” objection is a weird one. It seems to posit that competition was pretty lame until recently, which is pretty strange. One argument along these lines is in this article by Steve Wunsch, who considers the increase in airline fees “stark evidence of a deflationary spiral in those ticket prices caused by antitrust-induced competition.” This is odd, since airlines were deregulated in 1978 and have in recent years become less competitive if anything with the mergers of Delta/Northwest in 2009, United/Continental in 2010, Southwest/AirTran in 2011, and US Airways/American Airlines in 2013. A flaccid antitrust response from the Justice Department has allowed quasi-monopolies to develop in some travel hubs, which has tended to push fares higher rather than lower. The chart below shows the relationship between Jet Fuel prices and the CPI for airfares (both seasonally adjusted) for the 20 years ended in 2014, along with the most-recent point from last month.

The highly-explanatory R-squared of 0.81 suggests that there is not much wiggle room in airline pricing. Airfares are, as you would expect under a competitive industry, roughly cost-plus with the main source of variance being jet fuel prices. This is true even though we would expect that spread to vary over time. As Mr. Wunsch would argue, the highly competitive nature of the industry is holding down the non-commodity price pressures in airfares.

The only problem is that if you extend this graph to include the last three years, the R-squared drops about 10 points:

In case it isn’t clear from that chart, the last three years have seen airfares increasingly above what we would expect from the level of jet fuel prices. The next chart makes that clear I hope by plotting the residual (and 12-month moving average to smooth out seasonal issues such as one that evidently happened last month) between the actual CPI-airfare and the level that would be predicted from the 1994-2014 relationship. As you can see, prices have been higher, and increasingly so, than we would have thought, until this last month or two – and I wouldn’t grab a lot of comfort from that yet.

Not only is this not “stark evidence of a deflationary spiral in those ticket prices caused by antitrust-induced competition,” it seems to be stark evidence of inflation in ticket prices caused by a reduction in competition thanks to airline mergers.

In reading these many articles, it always is somewhat striking to me: everybody thinks their answer is “the” answer to the mystery. But most of these authors really don’t sufficiently understand how inflation works, and what the data is showing. This is apparent to those who do understand these nuances, as an author might discuss (as the one mentioned above did) an “aberration” in cell phone inflation as if the experts are stupid for expecting inflation when cell phone services only go down. The author clearly misunderstands what the “aberration” referred to even is; in this case the aberration was an enormous one-month collapse in prices that had never been seen and has not been repeated since. (For those who are curious about the aberration, and why it occurred, and why it is likely a methodology issue rather than sign of spiraling deflation in wireless services you can see my discussion of it here.)

The mystery is simple – the Fed’s models don’t work, and don’t take into account the fact that lower interest rates cause lower money velocity. They rely on a Phillips Curve effect that they think is broken because they don’t understand that the Phillips Curve relates wages and unemployment, not consumer prices and unemployment. They focus on a flawed measure like PCE rather than on something like Median CPI which, coincidentally, is a lot higher and suggests more price pressures. The mystery isn’t why inflation isn’t rising yet – the mystery is why they think there’s a mystery.

Some Further (Minor) Thoughts on the Phillips Curve

September 6, 2017 3 comments

Before I begin, let me say that if you haven’t read yesterday’s article, please do because it represents the important argument: the Phillips Curve doesn’t need rehabilitating, because it is working fine. In fact, I would argue that the Phillips Curve – relating wages to unemployment – is a remarkably accurate economic model prediction. The key chart from that article I reproduce here, but the article (which is brief) is worth reading.

Following my publication of that article, I had a few more thoughts that are worth discussing on this topic.

The first is historical. It’s incredibly frustrating to read article after article incorrectly stating what the Phillips Curve is supposed to relate. Of course one writer learns from another writer until what is incorrect becomes ‘common knowledge.’ I was fortunate in that, 30 years ago, I had excellent Economics professors at Trinity University in San Antonio, and I was reflecting on that fact when I said to myself “I wonder if Samuelson had it right?”

So I dug out my copy of Economics by Samuelson and Nordhaus (the best-selling textbook of all time, I believe, and the de rigeur Intro to Economics textbook for generations of economists). My copy is the 12th Edition, so perhaps they have corrected this since then…but on page 247, there it is – the Phillips Curve illustrated as a “tradeoff between inflation and unemployment.” Maybe that is where this error really propagated – with a Nobel Prize-winning economist making an error in his incredibly widely-read text! Interestingly, the authors don’t reference the original Phillips work, but refer to “writers in the 1960s” who made that connection, so to be fair to Samuelson and Nordhaus they were possibly already repeating an error that had been made even earlier.

My second point is artistic. In yesterday’s article, I said “The Phillips Curve…simply says that when labor is in short supply, its price goes up. In other words: labor, like everything else, is traded in the context of supply and demand,…” But students of economics will note that the Phillips Curve seems to obfuscate this relationship, because it is sloping the wrong way for a supply curve – which should slope up and to the right rather than down and to the right. This can be remedied by expressing the x-axis of the Phillips Curve differently – making it the quantity of labor demanded rather than the quantity of labor not demanded…which is what the unemployment rate is. So the plot of wage inflation as a function of the Employment Rate (as opposed to the Unemployment Rate) has the expected shape of a supply curve. More labor is supplied when the prices rise.

Again, this is nuance and not a really important point unless you want your economics to be pretty.

My third point, though, is important. One member of the bow-tied fraternity of Ph.D. economists told me through a friend that “the Phillips Curve has evolved to the relationship between Unemployment and general prices, not simply wages.” I am skeptical of any “evolution” that causes the offspring to be worse-adapted to the environment, but moreover I would argue that whoever led this “evolution” (and as I said above, it looks like it happened in the 1960s) didn’t really understand the way the economy (and in particular, business) works.

There is every reason to think that wages should be tied to available labor supply because one is the price of the other. That’s Microeconomics 101. But if unemployment is going to be a good indicator of generalized price inflation too, then it means that prices in the economy are essentially set as the price of the labor input plus a spread for profit. That is not at all how prices are set. Picture the businessperson deciding how to set prices. According to the “evolved Phillips Curve” understanding, this business owner looks at the wages he/she is paying and then sets the price of the product. But that’s crazy. A business owner considers labor as one input, as well as all of the other inputs, improvements in productivity in producing this good or service in question, competitive pressures, and the general state of the national and local economy. It would be incredible if all of these factors canceled out except for wage inflation, wouldn’t it? So in short, while I would expect that unemployment might have some explanatory power for inflation, I wouldn’t expect that explanatory power to be very strong. And, in fact, it isn’t. (But this isn’t new – it never has had any power.)


Come see our new store at!

The Phillips Curve is Working Just Fine, Thanks

September 5, 2017 2 comments

I must say that it is discouraging how often I have to write about the Phillips Curve.

The Phillips Curve is a very simple idea and a very powerful model. It simply says that when labor is in short supply, its price goes up. In other words: labor, like everything else, is traded in the context of supply and demand, and the price is sensitive to the balance of supply and demand.

Somewhere along the line, people decided that what Phillips really meant was that low unemployment caused consumer price inflation. It turns out that doesn’t really work (see chart, source BLS, showing unemployment versus CPI since 1997).

Accordingly, since the Phillips Curve is “broken,” lots of work has been done to resurrect it by “augmenting” it with expectations. This also does not work, although if you add enough variables to any model you will eventually get a decent fit.

And so here we are, with Federal Reserve officials and blue-chip economists alike bemoaning that the Fed has “only one model, and it’s broken,” when it never really worked in the first place. (Incidentally, the monetary model that relates money and velocity (via interest rates) to the price level works quite well, but apparently they haven’t gotten around to rediscovering monetarism at the Fed).

But the problem is not in our stars, but in ourselves. There is nothing wrong with the Phillips Curve. The title of William Phillips’ original paper is “The Relation between Unemployment and the Rate of Change of Money Wage Rates in the United Kingdom, 1861-1957.” Note that there is nothing in that title about consumer inflation! Here is the actual Phillips Curve in the US over the last 20 years, relating the Unemployment Rate to wages 9 months later.

The trendline here is a simple power function and actually resembles the shape of Phillips’ original curve. The R-squared of 0.91, I think, sufficiently rehabilitates Phillips. Don’t you?

I haven’t done anything tricky here. The Atlanta Fed Wage Growth Tracker is a relevant measure of wages which tracks the change in the wages of continuously-employed persons, and so avoids composition effects such as the fact that when unemployment drops, lower-quality workers (who earn lower wages) are the last to be hired. The 9-month lag is a reasonable response time for employers to respond to labor conditions when they are changing rapidly such as in 2009…but even with no lag, the R-squared is still 0.73 or so, despite the rapid changes in the Unemployment Rate in 2008-09.

So let Phillips rest in peace with his considerable contribution in place. Blame the lack of inflation on someone else.


Come see our new store at!

The Gold Price is Not ‘Too Low’

August 1, 2017 2 comments

Note: We are currently experimenting with offering daily, weekly, monthly, and quarterly analytical reports and chart packages. While we work though the kinks of mechanizing the generation and distribution of these reports, and begin to clean them up and improve their appearance, we are distributing them for free. You can sign up for a ‘free trial’ of sorts here.

Before I start today’s article, let me say that I don’t like to write about gold. The people who are perennially gold bulls are crazy in a way that is unlike the people who are perennial equity bulls (Abby Joseph Cohen) or perennial bond bulls (Hoisington). They will cut you.

That being said, they are also pretty amusing.

To listen to a gold bull, you would think that no matter where gold is priced, it is a safe haven. Despite the copious evidence of history that says gold can go up and down, certain of the gold bulls believe that when “the Big One” hits, gold will be the most prized asset in the world. Of course, there are calmer gold bulls also but they are similarly dismissive of any notion that gold can be expensive.

The argument that gold is valuable simply because it is acceptable as money, and money that is not under control of a central bank, is vacuous. Lots of commodities are not under the control of a central bank. Moreover, like any other asset in the world gold can be expensive when it costs too much of other stuff to acquire it, and it can be cheap when it costs lots less to acquire.

I saw somewhere recently a chart that said “gold may be forming a major bottom,” which I thought was interesting because of some quantitative analysis that we do regularly (indeed, daily) on commodities. Here is one of the charts, approximately, that the analyst used to make this argument:

I guess, for context, I should back up a little bit and show that chart from a longer-term perspective. From this angle, it doesn’t look quite like a “major bottom,” but maybe that’s just me.

So which is it? Is gold cheap, or expensive? Erb and Harvey a few years ago noticed that the starting real price of gold (that is, gold deflated by the price index) turned out to be strikingly predictive of the future real return of holding (physical) gold. This should not be terribly shocking – although it is hard to persuade equity investors today that the price at which they buy stocks may affect their future returns – but it was a pretty amazing chart that they showed. Here is a current version of the chart (source: Enduring Investments LLC):

The vertical line represents the current price of gold (all historical gold prices are adjusted by the CPI relative to today’s CPI and the future 10-year real return calculated to derive this curve). It suggests that the future real return for gold over the next decade should be around -7% per annum. Now, that doesn’t mean the price of gold will fall – the real return could be this bad if gold prices have already adjusted for an inflationary future that now unfolds but leaves the gold price unaffected (since it is already impounded in current prices). Or, some of each.

Actually, that return is somewhat better than if you attempt to fit a curve to the data because the data to the left of the line is steeper than the data to the right of the line. Fitting a curve, you’d see more like -9% per annum. Ouch!

In case you don’t like scatterplots, here is the same data in a rolling-10-year form. In both cases, with this chart and the prior chart, be careful: the data is fit to the entire history, so there is nothing held ‘out of sample.’ In other words, “of course the curve fits, because we took pains to fit it.”

But that’s not necessarily a damning statement. The reason we tried to fit this curve in the first place is because it makes a priori sense that the starting price of an asset is related to its subsequent return. Whether the precise functional form of the relationship will hold in the future is uncertain – in fact, it almost certainly will not hold exactly. But I’m comfortable, looking at this data, in making the more modest statement that the price of gold is more likely to be too high to offer promising future returns than it is too low and likely to provide robust real returns in the future.

Reversing the “Portfolio Balance Channel”

Note: We are currently experimenting with offering daily, weekly, monthly, and quarterly analytical reports and chart packages. While we work though the kinks of mechanizing the generation and distribution of these reports, and begin to clean them up and improve their appearance, we are distributing them for free. You can sign up for a ‘free trial’ of sorts here.

Today I want to write about something that’s been bothering me a bit recently. It’s about the Fed’s impending decision to start drawing down its balance sheet over some number of years (whether or not we have an announcement about that at tomorrow’s meeting, it seems likely that “balance sheet reduction” is on tap for later this year). Something had been gnawing at me about that, and until now I haven’t been able to put my finger on it.

It concerns the ‘portfolio balance channel.’ This bit of Fed arcana is part of how the central bank explained the importance of the practice of buying trillions in Treasury bonds. Remember that back when the Fed first started doing Large-Scale Asset Purchases (LSAP), they were concerned that a lack of ‘animal spirits’ were causing investors to shy away from taking risk in the aftermath of the credit crisis. Although this is entirely normal, to the FOMC it was something to be corrected – if people and firms aren’t willing to take risk, then it is difficult for the economy to grow.

So, as the Fed explained it, part of the reason that they were buying Treasuries is that by removing enough safe securities from the market, people would be forced to buy riskier securities. When QE1 started, 10-year TIPS were yielding 2.5%, and that’s a pretty reasonable alternative to equities in a high-risk environment. But the Fed’s ministrations eventually pushed TIPS yields (along with other yields, but by focusing on real rates we can abstract from the part of that decline that came from declining inflation expectations rather than the forced decline in real yields) down to zero in 2011, and eventually deeply negative. As expected, despite the risk aversion being experienced by investors they began to move into equities as the “only game in town” – think about how many times you’ve heard people lament they own equities because ‘there’s nothing else worth owning’? The eventual result, of course, was that expected returns to equities began to fall in line with the (manipulated) expected returns to other securities, until we got the current situation where, according to our calculations, TIPS now have a higher expected real return than equities again (but at a much lower level).

What was bothering me, of course, was that shrinking the balance sheet also implies reversing the “portfolio balance channel.” Via QE, the Fed forced investors into stocks because there were fewer Treasury securities outstanding; every time the Fed bought $1 of bonds, some fraction of that went into stocks. The reverse must also be true – for every $1 of bonds the Fed sells, some fraction of that money must come out of stocks.

I’m not the first person to note that reducing the balance sheet should be a negative for equities since it “reduces liquidity.” But I was always uncomfortable with the vagueness of the “liquidity” mechanism…after all, lots of people predicted cataclysm when the Fed “tapered” QE. The reversal of the portfolio balance channel, though, is a real effect. The money to buy the extra bonds that will be on the market – bonds not held by the Fed must be held by someone, after all – will come from somewhere. And some of that “somewhere” will be from equities, some from real estate, some from cash, etc. I don’t know how big an effect it will be, but I know the sign.

Inflation-Linked Bonds: For the Wary, but the “Wise?”

Only a quick article at the moment. This is longer than a tweet-length answer, but didn’t need to be super long.

A friend sent me the link to the following article from the FT:

Will UK inflation-linked bonds be the choice of the wise?

I must confess I don’t know about the answer to that question, although it is true that UK linkers – especially long linkers – are perennially rich thanks to pension fund demand. Below is a chart (source: Enduring Investments) that shows our analytical rich/cheap series for 10-year UK linkers.

But the article also includes a common gripe about inflation-linked bonds that isn’t really fair, and should be addressed. The argument is that inflation-linked bonds don’t really protect against inflation, because changes in real yields are much more impactful to the return than are changes in inflation.

This is true. It is also true that changes in nominal yields are much more impactful to the return of nominal bonds than is the coupon rate or yield on the bond. If you buy a 10-year Treasury yielding, say, 3%, and hold it for two years, you will most likely get a return quite a bit different from 3% because changes in the yield-to-maturity over that period overwhelms the yield of the bond (especially now). You only get 3% if you hold to maturity. (Well, technically you get 3% if you hold for a period equal to the Macaulay duration, but that’s a discussion for another time.)

So it isn’t fair to criticize inflation-linked bonds for not being an inflation hedge over every time period. As with nominal bonds, they are a perfect inflation hedge if held to the proper horizon, and a less-than-perfect hedge over different time periods.

However, you shouldn’t be trying to hedge inflation over the next week or month. You should be trying to hedge inflation over the long term. Accordingly, the fact that returns vary due to changes in real yields is not a damning fact about linkers. Unless, of course, you’re a highly levered participant.

Categories: Bond Market, Quick One, Theory, TIPS, UK
%d bloggers like this: