He was tutored at the
After the revolution, Kondratiev pursued academic research. In 1919, he was appointed to a teaching post at the Agricultural Academy of Peter the Great. In October 1920 he founded the
In 1922, he published his first writing on long cycles., The World Economy and its Conjunctures During and After the War. His writing that capitalist economies were characterized by successions of expansion and decline contradicted the Marxist idea of the imminent collapse of capitalism.
In 1923, Kondratiev intervened in the debate about the "Scissors Crisis", following the general opinion of his colleagues. In 1923–25, he worked on a five-year plan for the development of Soviet agriculture. In 1924, after publishing his first book, presenting the first tentative version of his theory of major cycles, Kondratiev traveled to
Kondratiev's economic cycle theory held that there were long cycles of about fifty years. In the beginning of the cycle economies produce high cost capital goods and infrastructure investments creating new employment and income and a demand for consumer goods. However, after a few decades the expected return on investment falls below the interest rate and people refuse to invest, even as overcapacity in capital goods gives rise to massive layoffs, reducing the demand for consumer goods. Unemployment and a long economic crisis ensue as economies contract. People and companies save their resources until confidence begins to return and there is an upswing into a new capital formation period, usually characterized by large scale investment in new technologies.
A member of the People's Commissariat of Agriculture and a proponent of the Soviet New Economic Policy (NEP) supported by Vladimir Lenin, Kondratiev was influential with writings about agriculture and planning methodology. Influenced by his trips overseas, he advocated a market-led industrialization strategy emphasizing export of agricultural produce to pay for industrialization, following the Ricardian economics theory of comparative advantage. He proposed a plan for agriculture and forestry from 1924 to 1928. However, after the death of Lenin in 1924, Joseph Stalin, who favored complete government control of the economy, took control of the Communist Party. Kondratiev's influence quickly waned.
According to the late Harvard sociologist Carle C. Zimmerman, Kondratiev was reported to Soviet authorities by a member of the
His last letter was sent to his daughter, Elena Kondratieva, on 31 August 1938. In September 1938 during Stalin's Great Purge, he was subjected to a second trial, condemned to ten years without the right to correspond with the outside world. However, Kondratiev was executed by firing squad on the same day the sentence was issued. Kondratiev was 46 at the time of his execution.
In the 1970s, increased interest in business cycles led to the rediscovery of Kondratiev's work, including the first-time publication of a complete English translation of his seminal article "The Long Waves in Economic Life" in the journal Review (Fernand Braudel Center) in 1979 (the article was originally published in a German journal in 1926 and a partial English translation appeared in the journal The Review of Economic Statistics in 1935). This rediscovery of Kondratiev in English-speaking academia led to his theories being extended for the first time beyond economics as, for example, political scientists such as Joshua Goldstein and geographers such as Brian Berry extended the concept of Kondratiev long waves into their own fields. However, Kondratiev's theory remains controversial because, among other issues, of his ideas about the periodical character of the replacement of basic capital goods and the empirical possibility of coincidence in identifying long waves (i.e. that long waves are simply an epiphenomenon).
In 1987, the Soviet Union officially rehabilitated Kondratiev. His collected works were first translated into English by Stephen S. Wilson in 1998. In 1992, on the centenary of his birth, it was founded the International Foundation N.A. Kondratiev, at the hands of Russian academics, Elena Kondratieva and Italian economist Giancarlo Pallavicini, then first Western advisor to the Russian government for the reform of the economy, appointed vice president, along with Yurji Jacovetz, and Leonid Abalkin president.