Deflation is considered a problem in a modern economy because of the potential of a deflationary spiral and its association with the Great Depression, although not all episodes of deflation correspond to periods of poor economic growth historically.
In economic theory deflation is a general reduction in the level of prices, or of the prices of an entire kind of asset or commodity. Deflation should not be confused with temporarily falling prices; instead, it is a sustained fall in general prices. In the IS/LM model this is caused by a shift in the supply and demand curve for goods and interest, particularly a fall in the aggregate level of demand. That is, there is a fall in how much the whole economy is willing to buy, and the going price for goods. Because the price of goods is falling, consumers have an incentive to delay purchases and consumption until prices fall further, which in turn reduces overall economic activity - contributing to the deflationary spiral.
Since this idles capacity, investment also falls, leading to further reductions in aggregate demand. This is the deflationary spiral. The solution to falling aggregate demand is stimulus either from the central bank, by expanding the money supply, or by the fiscal authority to increase demand, and borrow at interest rates which are below those available to private entities.
In more recent economic thinking, deflation is related to risk, where the risk adjusted return of assets drops to negative, investors and buyers will hoard currency rather than invest it, even in the most solid of securities. This can produce the theoretical condition, much debated as to its practical possibility, of a liquidity trap. A central bank cannot, normally, charge negative interest for money, and even charging zero interest often produces less stimulative effect than slightly higher rates of interest. In a closed economy, this is because charging zero interest also means having zero return on government securities, or even negative return on short maturities. In an open economy it creates a carry trade and devalues the currency producing higher prices for imports without necessarily stimulating exports to a like degree.
In monetarist theory, deflation is related to a sustained reduction in the velocity of money or number of transactions. This is attributed to a dramatic contraction of the money supply, perhaps in response to a falling exchange rate, or to adhere to a gold standard or other external monetary base requirement.
Deflation is generally regarded negatively, as it is a tax on borrowers and on holders of illiquid assets, which accrues to the benefit of savers and of holders of liquid assets and currency. In this sense it is the opposite of inflation (or in the extreme, hyperinflation), which is a tax on currency holders and lenders (savers) in favor of borrowers and short term consumption. In modern economies, deflation is caused by a collapse in demand (usually brought on by high interest rates), and is associated with recession and (more rarely) long term economic depressions.
In modern economies, as loan terms have grown in length and financing is integral to building and general business, the penalties associated with deflation have grown larger. Since deflation discourages investment and spending, because there is no reason to risk on future profits when the expectation of profits may be negative and the expectation of future prices is lower, it generally leads to, or is associated with a collapse in aggregate demand. Without the "hidden risk of inflation", it may become more prudent just to hold onto money, and not to spend or invest it.
Deflation is, however, the natural condition of hard currency economies when the rate of increase in the supply of money is not maintained at a rate commensurate to positive population (and general economic) growth. When this happens, the available amount of hard currency per person falls, in effect making money scarcer; and consequently, the purchasing power of each unit of currency increases. The late 19th century provides an example of sustained deflation combined with economic development under these conditions.
Deflation also occurs when improvements in production efficiency lower the overall price of goods. Improvements in production efficiency generally happen because economic producers of goods and services are motivated by a promise of increased profit margins, resulting from the production improvements that they make. Competition in the marketplace often prompts those producers to apply at least some portion of these cost savings into reducing the asking price for their goods. When this happens, consumers pay less for those goods; and consequently deflation has occurred, since purchasing power has increased.
While an increase in the purchasing power of one's money sounds beneficial, it can actually cause hardship when the majority of one's net worth is held in illiquid assets such as homes, land, and other forms of private property. It also amplifies the sting of debt, since-- after some period of significant deflation-- the payments one is making in the service of a debt represent a larger amount of purchasing power than they did when the debt was first incurred. Consequently, deflation can be thought of as a phantom amplification of a loan's interest rate.
This lesson about protracted deflationary cycles and their attendant hardships has been felt several times in modern history. During the 19th century, the Industrial Revolution brought about a huge increase in production efficiency, that happened to coincide with a relatively flat money-supply. These two deflationary catalysts led, simultaneously, not only to tremendous capital development, but also to tremendous deprivation for millions of people who were ill-equipped to deal with the dark side of deflation. Business owners-- on average, better educated in economic theory than their unfortunate cohorts (or just better able to withstand the economic stresses) -- recognized the deflation cycle as it unfolded, and positioned themselves to leverage its beneficial aspects.
Hard money advocates argue that if there were no "rigidities" in an economy, then deflation should be a welcome effect, as the lowering of prices would allow more of the economy's effort to be moved to other areas of activity, thus increasing the total output of the economy. However, while there have been periods of 'beneficial' deflation (especially in industry segments, such as computers), more often it has led to the more severe form with negative impact to large segments of the populace and economy.
Since deflationary periods favor those who hold currency over those who do not, they are often matched with periods of rising populist sentiment, as in the late 19th century, when populists in the United States wanted to move off hard money standards and back to a money standard based on the more inflationary (because more abundantly available) metal silver.
Most economists agree that the effects of modest long-term inflation are less damaging than deflation (which, even at best, is very hard to control). Deflation raises real wages which are both difficult and costly for management to lower. This frequently leads to layoffs and makes employers reluctant to hire new workers, increasing unemployment.
From a monetarist perspective deflation is caused primarily by a reduction in the velocity of money and/or the amount of money supply per person.
In modern credit-based economies, a deflationary spiral may be caused by the (central bank) initiating higher interest rates (i.e., to 'control' inflation), thereby possibly popping an asset bubble or the collapse of a command economy which has been run at a higher level of production than it could actually support. In a credit-based economy, a fall in money supply leads to markedly less lending, with a further sharp fall in money supply, and a consequent sharp fall-off in demand for goods. Demand falls, and with the falling of demand, there is a fall in prices as a supply glut develops. This becomes a deflationary spiral when prices fall below the costs of financing production. Businesses, unable to make enough profit no matter how low they set prices, are then liquidated. Banks get assets which have fallen dramatically in value since the (mortgage) loan was made, and if they sell those assets, they further glut supply, which only exacerbates the situation. To slow or halt the deflationary spiral, banks will often withhold collecting on non-performing loans (as in Japan, most recently). This is often no more than a stop-gap measure, because they must then restrict credit, since they do not have money to lend, which further reduces demand, and so on.
In unstable currency economies, barter and other alternate currency arrangements such as dollarization are common, and therefore when the 'official' money becomes scarce (or unusually unreliable), commerce can still continue (e.g., most recently in Russia and Argentina). Since in such economies the central government is often unable, even if it were willing, to adequately control the internal economy, there is no pressing need for individuals to acquire official currency except to pay for imported goods. In effect, barter acts as protective tariff in such economies, encouraging local consumption of local production. It also acts as a spur to mining and exploration, since one easy way to make money in such an economy is to dig it out of the ground.
When the central bank has lowered nominal interest rates all the way to zero, it can no longer further stimulate demand by lowering interest rates. This is the famous liquidity trap. When deflation takes hold, it requires "special arrangements" to "lend" money at a zero nominal rate of interest (which could still be a very high real rate of interest, due to the negative inflation rate) in order to (artificially) increase the money supply.
This cycle has been traced out on the broad scale during the Great Depression. International trade contracted sharply, severely reducing demand for goods, thereby idling a great deal of capacity, and setting off a string of bank failures. A similar situation in Japan, beginning with the stock and real estate market collapse in the early 1990s, was arrested by the Japanese government preventing the collapse of most banks and taking over direct control of several in the worst condition. These occurrences are the matter of intense debate. There are economists who argue that the post-2000 recession had a period where the US was at risk of severe deflation, and that therefore the Federal Reserve central bank was right in holding interest rates at an "accommodative" stance from 2001 on.
Increased productivity, however, can appear to cause deflation; but it is not general deflation; as the price of produced goods falls, while labor rates remain constant. Austrians show this as a benefit of sound money, which increases or decreases very little in total supply. Prices should simply confer the exchange ratio between any two goods in an economy. Increased productivity generally means less labor for more goods, whereas increased money supply should mean the same amount of labor for the same amount of goods.
For instance if there is a fixed money supply of 400 kg of gold in an economy that produces 200 widgets, then one widget will cost 2 kg of gold. However, next year if output is 400 widgets with the same money supply of 400 kg of gold the price of each widget will drop to 1 kg of gold. In this case the general fall in price was caused by increased productivity.
The opposite of the above scenario has the same effect on prices, but a different cause. If there is a fixed money supply of 400 kg of gold in an economy that produces 200 widgets, then once again each widget will cost 2 kg of gold. However, if next year the money supply is cut in half to 200 kg of gold with the same output of 200 widgets, the price of each widget will now only be 1 kg of gold. When capital profits are dropping rapidly, there is no reason to invest gold, which breaks the savings identity, and thus the automatic tendency of the economy to move back to equilibrium.
Austrians view increased productivity to be a good cause of a general fall in prices, while credit/money supply contraction as being a bad cause of a general fall in prices. Austrians also take the position that there are no negative distortions in the economy due to a general fall in prices in the first scenario. However, in the second scenario where a general fall in prices is caused by deflation, Austrians contend that this confers no benefit to society. For in this scenario wages will simply be cut in half and lower prices will not reflect a general increase in wealth.
Also, Austrians believe that some entity being able to inflate or deflate a money supply is given a privilege, as all prices will not change both simultaneously and proportionally. Rather price changes will occur as a response to what seems to be changes in demand, although this is only in nominal terms. Those who can inflate or deflate the money supply (or those closest to this source) can take advantage of an otherwise unknown change in the money supply by making exchanges that appear sound in nominal terms, but actually confer more profitable exchange rates in real terms, once prices have adjusted to the change.
For example, if a widget costs 5g of gold today and there is 20g of gold in the money supply, if the central bank decreases the money supply to 10g, it can sell its widgets for the formerly agreed upon price. Once the market finds less overall demand, however, prices will halve. While the central banks' money supply deflation was the cause of the price decrease, it received double the money for its widgets that they are now worth in real terms.
For a given money supply, if wages rise faster than productivity, profits will fall, and with them the price of producing goods (deflation), while consuming goods will rise (inflation). This happens in times when labor supply is tight and bargaining power is strong (prior to mid 1970s). When wages rise slower than productivity, profits rise as do the prices of assets relative to consuming goods. This can occur when labor supply is great and bargaining power is weak (mid 1970s to present).
Inflation and deflation occur when the economic policies allow wages to increase or decrease at differing rates than productivity. Wages rising faster than productivity lead to inflation. Wages failing to increase at the rate of productivity for protracted periods will ultimately cause deflation.
Indeed, if growth continues despite lagging wages, it is because of debt accumulation, producers lend to wage earning consumers part of their profits, in order to sell their products. For protracted periods, there is a lot of endogenous money creation. The debt/GDP ratio rises.
Then, when debt payments exceed the borrower's ability to pay, debt accumulation and endogeneous money creation stops, demand and goods' prices fall (deflation), manufacturers reduce production, employment falls, and fewer borrowers are thus able to pay their debts, and the cycle exacerbates.
Once preventive action has failed, Keynesians advocate corrective action. In case of debt deflation, Keynesians advocate "pump priming" or government creation of fiat money. As witnessed since 1990 in Japan, and in the 1930s in the USA, this policy is not very effective unless government creates employment via public works projects or military manufacturing.
Austrians and Keynesians agree on the idea that there are counterproductive cycles of booms and bust but while the former believe the government tends to be a cause of those cycles, the latter believe it is a means to reduce the size of those cycles.
Nominal prices are always somewhat sticky due to institutional factors, therefore a monetary deflation can lead to widespread bankruptcy. Prices fall over a long period of time, as institutional barriers need be broken (ie contract commitments) before the downward price spiral can be fully transmitted to other sectors.
Until the 1930s, it was commonly believed by economists that deflation would cure itself. As prices decreased, demand would naturally increase and the economic system would correct itself without outside intervention.
This view was challenged in the 1930s during the Great Depression. Keynesian economists argued that the economic system was not self correcting with respect to deflation and that governments and central banks had to take active measures to boost demand through tax cuts or increases in government spending. Reserve requirements from the central bank were high and the central bank could then have effectively increased money supply by simply reducing the reserve requirements and through "open" market operations (e.g., buying treasury bonds for cash) to offset the reduction of money supply in the private sectors due to the collapse of credit (credit is a form of money).
With the rise of monetarist ideas, the focus in fighting deflation was put on expanding demand by lowering interest rates (i.e., reducing the "cost" of money). This view has received a setback in light of the failure of accommodative policies in both Japan and the US to spur demand after stock market shocks in the early 1990s and in 2000 - 2002, respectively. Economists now worry about the (inflationary) impact of monetary policies on asset prices. Sustained low real rates can be the direct cause of higher asset prices and excessive debt accumulation. Therefore lowering rates may prove only a temporarily palliative, leading to the aggravation of an eventual future debt deflation crisis.
The first was the recession of 1836, when the currency in the United States contracted by about 30%, a contraction which is only matched by the Great Depression. This "deflation" satisfies both definitions, that of a decrease in prices and a decrease in the available quantity of money.
"The Great Sag of 1873-96 could be near the top of the list. Its scope was global. It featured cost-cutting and productivity-enhancing technologies. It flummoxed the experts with its persistence, and it resisted attempts by politicians to understand it, let alone reverse it. It delivered a generation’s worth of rising bond prices, as well as the usual losses to unwary creditors via defaults and early calls. Between 1875 and 1896, according to Milton Friedman, prices fell in the United States by 1.7% a year, and in Britain by 0.8% a year.
The deflation of the Great Depression, as in 1836, did not begin because of any sudden rise or surplus in output. It occurred because there was an enormous contraction of credit (money), bankruptcies creating an environment where cash was in frantic demand, and the Federal Reserve did not adequately accommodate that demand, so banks toppled one-by-one (because they were unable to meet the sudden demand for cash— see Fractional-reserve banking). From the standpoint of the Fisher equation (see above), there was a concomitant drop both in money supply (credit) and the velocity of money which was so profound that price deflation took hold despite the increases in money supply spurred by the Federal Reserve.
Systemic reasons for deflation in Japan can be said to include: