Are we too complacent on interest rates?

One of the ongoing puzzles in the current conjuncture is why interest rates remain so low, despite the fact that the global economy has turned the corner. Indeed, central banks have recently been subject to widespread criticism for maintaining them at levels consistent with the emergency rates required in 2009 when the economy does not face anything like the same degree of danger. Despite the fact that the Federal Reserve has raised interest rates on three occasions since December 2015, yields on the 10-year Treasury note are still lower than in summer 2014 whilst UK 10-year gilts are trading just above 1% and 10-year Bunds below 0.4%.

Looking at the issue in a longer-term context, the standard approach in the academic literature is to point out that the neutral global real interest rate has fallen over the past three decades. A Bank of England Working Paper published in December 2015 highlighted that the long-term risk free real rate has fallen by around 450 bps in both emerging and developed economies since the 1980s.

The major factors which drive underlying long-term rates are expectations of trend growth and factors which impact on savings and investment preferences. The authors (Rachel and Smith) point out that the impact of a growth slowdown on lower rates is limited, accounting for less than a quarter of the total observed amount, and that the bulk of this can be attributed to changes in savings and investment preferences. Their key finding is that whilst there has been a sharp rise in saving preferences across the globe, desired investment levels have also fallen significantly. This is, of course, fully consistent with the savings glut hypothesis first postulated by Ben Bernanke in 2005. But Rachel and Smith go further by giving some quantitative estimates for the magnitudes of the quantities involved. Thus, they attribute 100 of the 450 bps decline in real rates to slower global growth; 90 bps to demographic factors and 70 bps to lower investment demand. All told, once they account for a number of other factors, they claim to account for 400 bps of the decline in real rates.

As an academic tour de force, this paper is an excellent and comprehensive overview of the factors driving rates lower. But it is not the whole story. A quick look at the data, compiled by King and Low in 2014 (chart), suggests that whilst there was indeed a sharp decline in the global real rate between 1990 and 2008 of around 250 bps, the last 200 bps has occurred post-financial crisis – a period when central banks slashed the short end of the curve to zero at the same time as they were engaged in huge asset purchases. In order to probe a little deeper, it is worth highlighting the concept of the natural rate of interest, postulated by Swedish economist Knut Wicksell at the end of the 19^th century. Wicksell argued that if the market rate exceeded the natural rate, prices would fall; if it fell below, prices would rise. Obviously, we do not know what the natural rate is but a quick-and-dirty method is to measure the difference between nominal GDP growth and the interest rate to assess the extent to which the real and financial sectors of the economy are misaligned.

In the UK, over the period 1975 to 2007, nominal GDP growth was on average within 30 bps of Bank Rate but since 2010 it has averaged a full 300 bps above, and similar deviations have been recorded in the US and the euro zone. This is not proof that interest rates are too low. After all, it is not as if price inflation is a problem for the global economy. But it does highlight the extent to which the interest rate on financial assets is too low relative to returns on real assets, which in turn has helped to propel financial asset prices to stratospheric levels. The concern is clearly that at some point asset markets will turn. But central banks will probably have no choice but to watch the bubble deflate because after having used a huge amount of monetary resources to pump markets up, they cannot realistically deploy more to cushion the fall.

Whilst I understand why central banks have been reluctant to raise interest rates so far – although the Fed is now grasping the nettle – I do detect a slight note of complacency. The fact  that (some) central bankers have justified their low interest rate policy on the basis of lower global equilibrium rates, without fully accounting for the fact that their actions have themselves pushed global rates down, strikes me as distorted logic. I am reminded of the situation a decade ago when many central bankers dismissed rapid growth in monetary aggregates as a problem not worth worrying about, when in fact it reflected the actions of banks to pump up their balance sheets. And we all know how that ended.