Quantitative aspects of the relationship between theories of economic growth and economic cycles

This paper discovers some problems that take place in the economic growth theories and in their relationship with the economic cycle models. The author shows that, if the long-term economic trend formation is considered regardless of the economic activity fluctuations, whose impact is eliminated by numerous assumptions that distort economic reality (those about perfect competition, full employment, etc.), it would lead to some difficulties in identification of real economic situation and in the accuracy of macroeconomic forecasting. Demonstrated the nature of this kind of difficulties considering schematically the process of economic trends formation. Since the economic growth theories only deal with the long-term trend, abstracting through various assumptions from short-term fluctuations in economic activities, a stereotype of independence from fluctuations in economic activity can be created. An example of this is the identification by some of economists of the problem of the economic growth slowing down for the world economy (and the US economy, in particular) in the last decades of the 20th century and attempts to explain this slowdown. These explanations are mostly aimed at justifying the reason for the change in the inclination of the long-term trend of economic growth, which is assumed straightforward for at least 25 years. However, the inclination of this 25-year trend depends significantly on the choice of the period of time for which it is calculated. The work shows that another choice of time period for calculating a long-term trend for the US economy can prove that there is no such a problem as the slowdown in economic growth over time. Calculations, presented in the paper, show, in particular, that it is impossible to ensure sustainable economic growth in the long run, if you allow deep recessions in the short term. When choosing a period of time, which determines the long-term trend of economic growth, it is necessary to take into account the configuration of economic cycles, since it is the depth of lowest and highest points of the real fluctuation curve that determines the inclination of the trend of economic development. In other words, the future long-term trend is shaped today based on short-term fluctuations in real time. And all the drawbacks of regulating the cycles that have arisen today will somehow affect the slope of the long-term trend.