In economics, Kondratiev waves, also called cycles or surges, occasionally also referred to as the K-waves, are the term for a regular S-shaped cycle in the modern world economy. Fifty to sixty years in length, it consists of an alternation of periods of high sectoral growth with periods of slower growth. The pattern is more visible in international production data than in individual national economies and concerns output rather than prices. Some economists divide the Kondratiev wave into two 'seasons'; the Kondratiev Fall and the later part, the Kondratiev Winter. A bull market is associated with 'fall' and a bear market with 'winter'. More common today is the division into four periods with a turning point (collapse) between the first and second two. Economics (deriving from the Greek words οίκω [oeko], house, and νέμω [nemo], distribute) is the social science that studies the allocation of scarce resources through measurable variables. ... A bull market is a financial market where prices of instruments (e. ... A Bear Market is a phase in the life of a stock market or other financial market in which the value of most listed shares of stock fall consistently, or values in a financial market trend downward, as reflected by a downward movement of one or more key stock indexes...

The Russian economist Nikolai Kondratiev (1892-1931) was the first to bring forward these observations in the 1920s. Early on four schools of thought emerged as to why capitalist economies have these longwaves. These schools of thought revolved around innovations, capital investment, war and capitalist crisis. Nikolai Kondratiev (1892-1938) was a Russian economist. ... Sometimes referred to as the Roaring Twenties. Events and trends Technology John T. Thompson invents Thompson submachine gun, also known as Tommy Gun. ...

According to the innovation theory, these waves arise from the bunching of basic innovations that launch technological revolutions that in turn create leading industrial or 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. Since first originated, various studies have expanded the range of possible cycles, finding longer or shorter cycles in the data. Joseph Alois Schumpeter (February 8, 1883 – January 8, 1950) was one of the greatest 20th century economists and one of the best read. ... Events and trends Technology Jet engine invented First atom was split with a particle accelerator Golden Age of radio begins in U.S. Science Nuclear fission discovered by Otto Hahn, Lise Meitner and Fritz Strassmann Pluto, the ninth planet from the Sun, is discovered by Clyde Tombaugh British biologist Arthur...

The theory is not accepted by most neo-classical ("standard textbook") economists, who necessarily see technical change and innovation as exogenous rather than endogenous to economics, but it is one of the bases of innovation-based, development, and evolutionary economics, i.e. the main heterodox stream in economics. Among ones who accept it, there has been no universal agreement about the start and the end years of particular waves, but most cycle theorists agree with the "Schumpeter-Freeman-Perez" paradigm of five waves so far since the industrial revolution, and the sixth one to come. These five cycles are

• The Industrial Revolution--1771
• The Age of Steam and Railways--1829
• The Age of Steel, Electricity and Heavy Engineering--1875
• The Age of Oil, the Automobile and Mass Production--1908
• The Age of Information and Telecommunications--1971

According to this theory, we are currently at the turning-point of the 5th Kondratiev.

External links

• http://cepa.newschool.edu/het/schools/business.htm