Central Banks have often used the term ‘the neutral rate’ which refers to a rate of interest that neither stimulates the economy nor restrains economic growth. This rate is often defined as the rate which is consistent with full employment, trend growth, and stable prices – an economy where neither expansionary nor contractionary measures need to be implemented.
The neutral interest rate is the rate of interest where desired savings equal desired investment, and can be thought of as the level of the OCR that is neither contractionary nor expansionary for the economy.
OCR > Neutral Rate = Contractionary and slowing down the economy
OCR < Neutral Rate = Expansionary and speeding up the economy
This neutral rate dictates when the RBNZ end their tightening or loosening cycle. If the neutral rate is seen to be 3% it is the expectation that the RNBZ will increase the OCR to 3%. The graph below shows the difference between the estimated neutral rate and the OCR. Note that:
2008 – positive gap as RBNZ trying to bring inflation under control – contractionary level
2019 – the gap narrows and monetary policy becomes less stimulatory as the neutral of the OCR is likely lower.
What determines the neutral rate of interest in an economy?
Supply of loanable funds (people who save money) and Demand to borrow money – neutral rate generates a level of savings and borrowing that delivers the economy to maximum sustainable employment and inflation – 2% in NZ but with Policy Target Agreement of 1-3%.
Potential growth rate of an economy – if people expect more growth = higher incomes = higher borrowing = upward pressure on neutral rates. Economists tend to look at the production function and how much we can produce in the long-run therefore impacting aggregate supply. With higher potential growth rates investment spending is expected to increase and with it interest rates.
Population growth – strong population growth = larger labour force = larger national output which supports the neutral rate of interest.
Age and life expectancy – higher life expectancy increases the amount that people save during their working years. If consumers buy now rather than later = potentially either lower saving rates and/or higher borrowing = neutral rate of interest rises.
Superannuation / retirement age – burden of funding retirees fall on a smaller working age population. This could require higher taxes which leads to less spending putting downward pressure on interest rates.
Debt – with low mortgage rates, debt servicing have been at record lows. People have therefore borrowed a lot money and now have high level of indebtedness levels. Therefore higher mortgage rates mean that consumers disposable income will be reduced.
Government debt – COVID-19 has led to increased government spending and bigger budget deficits. New Zealand economy is probably as sensitive to higher interest rates and an increase in rates by the RBNZ will be very influential, limiting how far interest rates have to rise. And with households and the Government already loaded up on debt, future borrowing capacity is now reduced, which will put downwards pressure on interest rates too.
Overseas investment – as New Zealand comes a more attractive place to invest it increase the supply of loanable funds to New Zealanders. The investment will also strengthen the dollar which make exports less competitive but imports cheaper. Global capital flows mean that we can’t get too far out of sync with other advanced economies – as long as global neutral rates continue their relentless move south, so too will New Zealand’s.
In New Zealand, as in most economies, estimates of the real neutral interest rate have been trending downwards over several
decades. In recent years, the RBNZ indicator suite suggests that the real neutral interest rate has stabilised at low levels. The RBNZ current average estimate for the real neutral OCR is around 0 percent. However, the wide range between the maximum and minimum values of RBNZ estimates demonstrates that there is significant uncertainty about the level of neutral interest rates, particularly since the beginning of the COVID-19 pandemic. RBNZ Monetary Policy Statement – November 2022. P. 30
Source: NZ Insight: Neutral interest rates – 20th August 2021 – ANZ Bank