Roubini: Výtečník Buffett podlehl přeludu, trhy se zřítí - Diskuze, názory, doporučení a hodnocení

The Deadly Dirty D-Words: “Deflation”, “Debt Deflation” and “Defaults”. And How Central Banks Will Have to Resort to “Crazy” Policies as We Have Reached Such Bermuda Triangle of a “Liquidity Trap”

Nouriel Roubini | Nov 21, 2008

The Costs and Dangers of Price Deflation

Before we discuss the monetary policy options in a deflation and liquidity trap let us consider the costs and dangers of deflation.

First, if aggregate demand falls sharply below aggregate supply then price deflation sets in (and indeed there is already massive price deflation in the US in the sectors – housing, autos/motor vehicles and consumer durables – where the excess inventory of unsold goods is huge). The fall in prices and the excess inventory of unsold goods forces firms to cut back production and employment; the ensuing fall in incomes leads to further fall in demand and induce another vicious cycle of falling prices and falling production/employment/income and demand.

Second, when there is deflation there is no incentive to consume/spend today as prices will be lower tomorrow: buying goods today is like catching a falling knife and there is an incentive to postpone spending (consumption and investment spending) until the future: why to buy a home or a car today if its price will fall another 15% and purchasing today would imply having one’s equity in a home or a car fully wiped out in a matter of months? Better to postpone spending. But this postponing of spending exacerbates the vicious cycle of falling demand and supply/employment/income and prices.

Third, when there is deflation real interest rate are high and rising in spite of the fact that nominal policy rates are zero. If the policy rate is zero and there is a 2% deflation the real short term policy rate is actually a positive 2% that further depresses consumption and investment; and real long-term market rates are even higher with deflation – as discussed in detail below – as market rates at which firms and households borrow are much higher than short term policy rates.

The Deadly Deeds of Debt Deflation

Fourth, deflation also leads to the nightmare of debt deflation, a situation well analyzed by Fisher during the Great Depression. If debt liabilities are in nominal terms (D) and at a fixed long term interest rate (i) a reduction in the price level (P) increases the real value of such nominal liabilities (D/P goes up); so debtors that are already distressed in a recession and deflation become even more distressed as the real burden of their liabilities (D/P) sharply rises.

Another complementary way to see the perverse effects of debt deflation is to notice that the ex-post – as opposed to the ex-ante –real interest rate faced by borrowers sharply rise. Suppose you are a firm or household that had borrowed – say a 10 year mortgage or a 10 year corporate bond – at an interest rate (i) of 5% at the time when inflation (dP/P) was expected to remain at 3%; then the real ex-ante real cost of borrowing (r= i – dP/P) was only 2% (the difference between 5% and the expected inflation of 3%). Now suppose that, ex-post, the economy falls into a deflation trap and prices are now falling at 2% annual rate and expected to fall as much for a number of years. Now the ex-post real interest rate (r= i – dP/P) on that borrowing rises from 2% ex-ante to an actual ex-post 7% (5% - (-2%)). Thus, ex-post unexpected deflation sharply increases the real interest rate faced by borrowers or, equivalently, sharply increases the real ex-post value of their real liabilities (D/P).

Things are even worse if the debtor had borrowed to finance the leverage purchase of assets whose prices is now falling. Suppose you are a household who borrowed at a 5% mortgage rate to purchase a home whose price is now falling at an annual rate of 15%. Then the effective real interest rate that you are facing on your debt is not 5% but a whopping 20% (the sum of the 5% mortgage rate plus the 15% fall in the price of the underlying asset) that soon leads you into the depth of negative equity into your home. Thus, leveraged purchase of assets whose price is falling is an even more deadly form of debt deflation.

In all of its forms and manifestations debt deflation sharply increases the risk that borrowers will be forced to default on real obligations that they cannot service. Thus, debt deflation is associated with a sharp rise in corporate defaults and household defaults that creates a spiral of deflation, debt deflation and defaults.

High Market Real Interest Rates and Costs of Borrowing in a Deflation/Liquidity Trap

In situations of deflation and liquidity trap traditional monetary policy becomes pathetically ineffective. Consider now why monetary policy is ineffective. The real long-term interest rate faced by borrowers (say a mortgage holders who has a 10 year fixed rate mortgage or a corporate who issues a 10 year nominal rate bond) is given by the following expression:

Real Long Term Market Rate = (Nominal Long Term Market Yield – Inflation Rate) = (Nominal Long Term Market Yield – Long Term Government Bond Yield) + (Long Term Government Bond Yie ...