Editing Kondratiev wave (section)

== Explanations of the cycle ==
=== Technological innovation theory ===
According to the innovation theory, these waves arise from the bunching of basic [[Diffusion of innovations#|innovations]] that launch [[technological revolution]]s that in turn create leading industrial or [[Commerce|commercial]] sectors. Kondratiev's ideas were taken up by [[Joseph Schumpeter]] in the 1930s. The theory hypothesized the existence of very long-run [[macroeconomic]] and price cycles, originally estimated to last 50–54 years.

In recent decades there has been considerable progress in historical economics and the history of technology, and numerous investigations of the relationship between technological innovation and economic cycles. Some of the works involving long cycle research and technology include Mensch (1979), [[Andrew Tylecote|Tylecote]] (1991), the International Institute for Applied Systems Analysis (IIASA) (Marchetti, Ayres), [[Christopher Freeman|Freeman]] and Louçã (2001), [[Andrey Korotayev]]<ref>{{cite journal|doi=10.1016/j.techfore.2011.02.011|title=Kondratieff waves in global invention activity (1900–2008)|year=2011|last1=Korotayev|first1=Andrey|last2=Zinkina |first2=Julia|last3=Bogevolnov|first3=Justislav|journal=Technological Forecasting and Social Change|volume=78|issue=7|pages=1280|url=https://www.academia.edu/1514533}}</ref> and [[Carlota Perez]].

Perez (2002) places the phases on a [[logistic function|logistic]] or ''S'' curve, with the following labels: the beginning of a technological era as irruption, the ascent as frenzy, the rapid build out as synergy and the completion as maturity.<ref name="Perez2002">{{cite book |title= Technological Revolutions and Financial Capital: The Dynamics of Bubbles and Golden Ages
|last1=Perez
|first1= Carlota
|year=2002 |publisher= Edward Elgar Publishing Limited |location=UK  |isbn=978-1-84376-331-4  |url=https://archive.org/details/technologicalrev00carl|url-access= registration
}}</ref>

=== Demographic theory ===
Because people have fairly typical spending patterns through their life cycle, such as spending on schooling, marriage, first car purchase, first home purchase, upgrade home purchase, maximum earnings period, maximum retirement savings and retirement, demographic anomalies such as baby booms and busts exert a rather predictable influence on the economy over a long time period. The [[Easterlin hypothesis]] deals with the post-war baby-boom. [[Harry Dent]] has written extensively on demographics and economic cycles. Tylecote (1991) devoted a chapter to demographics and the long cycle.<ref>{{Cite book
 | last1 = Tylecote
 | first1 = Andrew
 | title = The Long Wave in the World Economy
 | year = 1991
 |publisher=Routledge
 |location=London
 |pages= Chapter 5: Population feedback
 | isbn = 978-0-415-03690-0}}</ref>

=== Land speculation ===
{{main article|Georgism}}
[[Georgism|Georgists]] such as [[Mason Gaffney]], [[Fred Foldvary]] and [[Fred Harrison (author)|Fred Harrison]] argue that land speculation is the driving force behind the boom and bust cycle. Land is a finite resource which is necessary for all production and they claim that because exclusive usage rights are traded around, this creates speculative bubbles which can be exacerbated by overzealous borrowing and lending. As early as 1997, a number of Georgists predicted that a depression would occur in 2008.<ref>{{cite web |url=http://www.foldvary.net/Gutenberg/index.html |title=Fred Foldvary |publisher=Foldvary.net |access-date=2013-03-26 |archive-date=2008-10-19 |archive-url=https://web.archive.org/web/20081019044505/http://www.foldvary.net/Gutenberg/index.html |url-status=dead }}</ref>

=== Debt deflation ===
{{main article|Debt deflation}}
Debt deflation is a theory of [[economic cycle]]s which holds that recessions and [[depression (economics)|depressions]] are due to the overall level of debt shrinking (deflating). Hence, the [[credit cycle]] is the cause of the economic cycle.

The theory was developed by [[Irving Fisher]] following the [[Wall Street Crash of 1929]] and the ensuing [[Great Depression]]. Debt deflation was largely ignored in favor of the ideas of [[John Maynard Keynes]] in [[Keynesian economics]], but it has enjoyed a resurgence of interest since the 1980s, both in [[mainstream economics]] and in the [[heterodox economics|heterodox]] school of [[post-Keynesian economics]] and has subsequently been developed by such post-Keynesian economists as [[Hyman Minsky]]<ref>{{cite journal |first=Hyman |last=Minsky |title=The Financial Instability Hypothesis |year=1992 |journal=Jerome Levy Economics Institute Working Paper No. 74 |ssrn=161024 }}</ref> and [[Steve Keen]].<ref>{{cite journal |first=Steve |last=Keen |year=1995 |title=Finance and Economic Breakdown: Modelling Minsky's Financial Instability Hypothesis |journal=Journal of Post Keynesian Economics |volume=17 |issue=4 |pages=607–635 |doi= 10.1080/01603477.1995.11490053}}</ref>