Mainstream economic theories, such as the efficient market hypothesis, argue that asset prices generally reflect all available information, making large mispricings rare and financial crises difficult to predict.
Austrian theories Austrian School economists Ludwig von Mises and Friedrich Hayek discussed the business cycle starting with Mises'
Theory of Money and Credit, published in 1912.
Marxist theories Recurrent major depressions in the world economy at the pace of 20 and 50 years have been the subject of studies since
Jean Charles Léonard de Sismondi (1773–1842) provided the first theory of crisis in a critique of classical political economy's assumption of equilibrium between supply and demand. Developing an economic
crisis theory became the central recurring concept throughout
Karl Marx's mature work. Marx's
law of the tendency for the rate of profit to fall borrowed many features of the presentation of
John Stuart Mill's discussion
Of the Tendency of Profits to a Minimum (Principles of Political Economy Book IV Chapter IV). The theory is a corollary of the
Tendency towards the Centralization of Profits. In a capitalist system, successfully-operating businesses return less money to their workers (in the form of wages) than the value of the goods produced by those workers (i.e. the amount of money the products are sold for). This
profit first goes towards covering the initial investment in the business. In the long-run, however, when one considers the combined economic activity of all successfully-operating business, it is clear that less money (in the form of wages) is being returned to the mass of the population (the workers) than is available to them to buy all of these goods being produced. Furthermore, the expansion of businesses in the process of competing for markets leads to an abundance of goods and a general fall in their prices, further exacerbating
the tendency for the rate of profit to fall. The viability of this theory depends upon two main factors: firstly, the degree to which profit is taxed by government and returned to the mass of people in the form of welfare, family benefits and health and education spending; and secondly, the proportion of the population who are workers rather than investors/business owners. Given the extraordinary capital expenditure required to enter modern economic sectors like airline transport, the military industry, or chemical production, these sectors are extremely difficult for new businesses to enter and are being concentrated in fewer and fewer hands. Empirical and econometric research continues especially in the
world systems theory and in the debate about
Nikolai Kondratiev and the so-called 50-years
Kondratiev waves. Major figures of world systems theory, like
Andre Gunder Frank and
Immanuel Wallerstein, consistently warned about the crash that the world economy is now facing. World systems scholars and Kondratiev cycle researchers always implied that
Washington Consensus oriented economists never understood the dangers and perils, which leading industrial nations will be facing and are now facing at the end of the long
economic cycle which began after the
oil crisis of 1973.
Minsky's theory Hyman Minsky has proposed a
post-Keynesian explanation that is most applicable to a closed economy. He theorized that
financial fragility is a typical feature of any
capitalist economy. High fragility leads to a higher risk of a financial crisis. To facilitate his analysis, Minsky defines three approaches that financing firms may choose, according to their tolerance of risk. They are hedge finance, speculative finance, and
Ponzi finance. Ponzi finance leads to the most fragility. • for hedge finance, income flows are expected to meet financial obligations in every period, including both the principal and the interest on loans. • for speculative finance, a firm must roll over debt because income flows are expected to only cover interest costs. None of the principal is paid off. • for Ponzi finance, expected income flows will not even cover interest cost, so the firm must borrow more or sell off assets simply to service its debt. The hope is that either the market value of assets or income will rise enough to pay off interest and principal. Financial fragility levels move together with the
business cycle. After a
recession, firms have lost much financing and choose only hedge, the safest. As the economy grows and expected
profits rise, firms tend to believe that they can allow themselves to take on speculative financing. In this case, they know that profits will not cover all the
interest all the time. Firms, however, believe that profits will rise and the loans will eventually be repaid without much trouble. More loans lead to more investment, and the economy grows further. Then lenders also start believing that they will get back all the money they lend. Therefore, they are ready to lend to firms without full guarantees of success. Lenders know that such firms will have problems repaying. Still, they believe these firms will refinance from elsewhere as their expected profits rise. This is Ponzi financing. In this way, the economy has taken on much risky credit. Now it is only a question of time before some big firm actually defaults. Lenders understand the actual risks in the economy and stop giving credit so easily.
Refinancing becomes impossible for many, and more firms default. If no new money comes into the economy to allow the refinancing process, a real economic crisis begins. During the recession, firms start to hedge again, and the cycle is closed.
Banking School theory of crises The Banking School theory of crises describes a continuous cycle driven by varying interest rates. It is based on the work of
Thomas Tooke,
Thomas Attwood,
Henry Thornton,
William Jevons and a number of bankers opposed to the
Bank Charter Act 1844. Starting at a time when short-term interest rates are low, frustration builds up among investors who search for a better yield in countries and locations with higher rates, leading to increased capital flows to countries with higher rates. Internally, short-term rates rise above long-term rates causing failures where borrowing at short term rates has been used to invest long-term where the funds cannot be liquidated quickly (a similar mechanism was implicated in the March 2023 failure of
SVB Bank). Internationally, arbitrage and the need to stop capital flows, which caused bullion drains in the gold standard of the nineteenth century and drains of foreign capital later, bring interest rates in the low-rate country up to equal those in the country which is the subject of investment. The capital flows reverse or cease suddenly causing the subject of investment to be starved of funds and the remaining investors (often those who are least knowledgeable) to be left with devalued assets. Bankruptcies, defaults and bank failures follow as rates are pushed high. After the crisis governments push short-term interest rates low again to diminish the cost of servicing government borrowing which has been used to overcome the crisis. Funds build up again looking for investment opportunities and the cycle restarts from the beginning.
Coordination games Mathematical approaches to modeling financial crises have emphasized that there is often
positive feedback between market participants' decisions (see
strategic complementarity). Positive feedback implies that there may be dramatic changes in asset values in response to small changes in economic fundamentals. For example, some models of currency crises (including that of
Paul Krugman) imply that a fixed exchange rate may be stable for a long period of time, but will collapse suddenly in an
avalanche of currency sales in response to a sufficient deterioration of government finances or underlying economic conditions. According to some theories, positive feedback implies that the economy can have more than one
equilibrium. There may be an equilibrium in which market participants invest heavily in asset markets because they expect assets to be valuable. This is the type of argument underlying
Diamond and Dybvig's model of
bank runs, in which savers withdraw their assets from the bank because they expect others to withdraw too. Herding models, based on
Complexity Science, indicate that it is the internal structure of the market, not external influences, which is primarily responsible for crashes. In "adaptive learning" or "adaptive expectations" models, investors are assumed to be imperfectly rational, basing their reasoning only on recent experience. In such models, if the price of a given asset rises for some period of time, investors may begin to believe that its price always rises, which increases their tendency to buy and thus drives the price up further. Likewise, observing a few price decreases may give rise to a downward price spiral, so in models of this type, large fluctuations in asset prices may occur.
Agent-based models of financial markets often assume investors act on the basis of adaptive learning or adaptive expectations. These theories differ mainly in whether they emphasize market rationality, structural instability, financial leverage, behavioral factors, or institutional failures as the primary drivers of financial crises. ==2008 financial crisis==