French physician and economist who made detailed studies of cycles in business and trade.

Juglar qualified as a doctor in 1846. His medical training gave him an interest in population and demography, but it appears to have been the economic disturbances of 1848 that attracted him to the subject of economic fluctuations and crises. In 1851 he began contributing to the Journal des Économistes, and in 1860 he submitted an essay, Des Crises commerciales (published as a book, 1862; “Business Crises”), to the Academy of Moral and Political Science; it won the Bordin Prize.

Juglar was one of the first to analyze business cycles (business cycle) as fully as possible on the basis of available time series data. His use of statistics in predicting turning points in cycles was so accurate that a later economic cycle theorist, Joseph Schumpeter (Schumpeter, Joseph A.), wrote of him as being “among the greatest economists of all time.” He paid particular attention to the behaviour of bank balances, which he regarded as a barometer of commercial affairs.