AbstractsPhysics

Introduction: The most apparent characteristic of the modern world economy is change, various in type, frequent in occurrence, and often striking. It is to be expected that economists have tried to approach these changes analytically and determine their causes, and their nature, and in so doing have achieved a certain measure of success. As Kuznets (20) remarked in 1930, *Economists know a good deal about cyclical fluctuations and seasonal changes. They know little of the nature of random variations. On the subject of secular or long-time movements, what is said rests upon a small volume of vague knowledge combined with fervent beliefs."