Jevons was a British economist (1835-1882), who is considered, along with Carl Menger and M.-E.-L. Walras, a co-founder of marginalism and theory of utility. Jevons is the author of the book “The Theory of Political Economy”, 1871, in which he devised the concept of marginal utility, from an additive and separable utility function, although it was not measurable on cardinal terms. These studies were possible thanks to Johann H. von Thünen’s works, who was the first economist to use the word “marginal”, which meaning Jevons adopted in his works using the term “final”. He is also considered as a precursor of Econometrics for his work on business cycle, index numbers and moving averages, topics on which he used his extensive knowledge of mathematics.

Although his works on marginal utility are considered pioneer during the marginal revolution, and important for the development of neoclassical economics, Jevons considered there would be only one possible solution when considering barter exchange. However, there are infinite solutions, as was demonstrated later on by Francis Y. Edgeworth, whose indifference curves are based on Jevons’ earlier work.

Pareto was an economist and sociologist of Italian origin, born in Paris (1848-1923), who taught at the University of Lausanne, as well as previously did his mentor, Léon Walras. They both were part of the Lausanne School, which is considered, along with the Austrian School, as the birthplace of marginalism and neoclassical economics.

His chief works were “Course of Political Economy”, 1896-97, and “Manual of Political Economy”, 1906. Among Pareto’s contributions, we can highlight the graphical development of Edgeworth box, as well as an improvement on the way indifference curves are drawn, and studies on the personal distribution of income.

In his studies of the late nineteenth century, Pareto found some regularity in the personal distribution of income in different countries. From that regularity, he determined a series of economic and sociological conclusions, which became known afterwards as Pareto’s Laws. He also studied some regularities in businesses, where concentration was the explanation for the fact that many companies get 80% of their revenue from only 20% of its products.

Nowadays, however, he is mostly known for the Pareto optimal, a notion widely used in game theory and welfare economics.

Malthus was an English reverend (1766-1843), who in his book “An Essay on the Principles of Population,” wrote an argument against his contemporary Mr. Godwin, who believed in unlimited population growth. Malthusian population theory warned of the possibility, that while the population grew geometrically, food resources grew only in arithmetical proportion, thus creating the conditions for a shortage in the long term that would require an adjustment in the birth rate. This law of Malthus’s population was severely criticized by Karl Marx, another heterodox economist from the Classical school of economics, who called the parish of Albury “advocate of the bourgeoisie.” The principles of Malthus had great influence on the thinking of Darwin and Wallace about the struggle for life as the source of the natural selection of the strongest.

In his “Principles of Political Economy”, Malthus explained how he was against Say’s Law, by considering demand as an aggregate. Thus, if wages were to be mantained at a subsistence level, aggregate demand would drop. Therefore there would be a production surplus, idea that would be used by J.M. Keynes in his “The General Theory of Employment, Interest and Money”.

Simon Smith Kuznets, 1901-1985, was a Russian born American economist, Professor at Harvard University. His main works were related with the economic growth of nations.  He won the Nobel Prize in Economic Sciences in 1971. Kuznets was granted this award for the use of empirical methods in order to understand better the economic and social structure and economic growth. His works helped to understand the behaviour of economic cycles and described an economic cycle of 15-25 years known as the Kuznets Swing.

Kuznets developed a series of empirical studies using statistic models that supported J.M. Keynes ideas initially, but then redesigned his studies in order to analyse a longer period of time, and his conclusions differed from the previous ones.

Other studies by Kuznets deal with inequality in wealth distribution. As the Kuznets’ curve shows, inequality increases in the short term of economic growth, but it ends up decreasing in the long term. He frequently expressed his opinion that GDP per capita was not an accurate measure of welfare.

In 1940 he stated that the US economy was not working at its full capacity and was one of the designers of the Victory Plan in order to maximize the war economy during World War II.