Current statements from central bankers around the world argue that current low real interest rates reflect a change in the “neutral” rate, and is linked to demographic shifts, investment patterns and globalisation. In other words, monetary policy is NOT to blame – they are simply reacting.
However, an interesting (and complex) working paper Why so low for so long? A long-term view of real interest rates? from the Bank for International Settlement raises serious questions about the assumption which Central Banks are working with. In fact, their analysis suggests that monetary policy is the cause of the low rates, not a reaction to them and this has long range impact. This turns current thinking on its head. Central Bankers policy have driven rates lower!
Global real (inflation-adjusted) interest rates, short and long, have been on a downward trend throughout much of the past 30 years and have remained exceptionally low since the Great Financial Crisis (GFC). This has triggered a debate about the reasons for the decline. Invariably, the presumption is that the evolution of real interest rates reflects changes in underlying saving-investment determinants. These are seen to govern variations in some notional “equilibrium” or natural real rate, defined as the real interest rate that would prevail when actual output equals potential output, towards which market rates gravitate.
Prevailing explanations of the decline in real interest rates since the early 1980s are premised on the notion that real interest rates are driven by variations in desired saving and investment.
But based on data stretching back to 1870 for 19 countries, our systematic analysis casts doubt on this view. The link between real interest rates and saving-investment determinants appears tenuous. While it is possible to find some relationships consistent with the theory in some periods, particularly over the last 30 years, they do not survive over the extended sample. This holds both at the national and global level. By contrast, we find evidence that persistent shifts in real interest rates coincide with changes in monetary regimes. Moreover, external influences on countries’ real interest rates appear to reflect idiosyncratic variations in interest rates of countries that dominate global monetary and financial conditions rather than common movements in global saving and investment. All this points to an underrated role of monetary policy in determining real interest rates over long horizons.
Overall, our results raise questions about the prevailing paradigm of real interest rate determination. The saving-investment framework may not serve as a reliable guide for understanding real interest rate developments. And inflation may not be a sufficiently reliable signal of where real interest rates are relative to some unobserved natural level. Monetary policy, and financial factors more generally, may have an important bearing on persistent movements in real interest rates.
Note: BIS Working Papers are written by members of the Monetary and Economic Department of the Bank for International Settlements, and from time to time by other economists, and are published by the Bank. The papers are on subjects of topical interest and are technical in character. The views expressed in them are those of their authors and not necessarily the views of the BIS.
