In a Market with Many Buyers and Sellers, the Price Reflects the Valuations of the Buyer Least Willing to Buy and the Seller Least Willing to Sell (the “Marginal Pairs”)

Menger sought to explain prices as the outcome of the purposeful, voluntary interactions of buyers and sellers, each guided by their own subjective evaluations of the usefulness of various goods and services (what we now call marginal utility, a term later coined by Friedrich von Wieser). Trade is thus the result of people’s deliberate attempts to improve their well-being, not an innate “propensity to truck, barter, and exchange,” as suggested by Adam Smith. The exact quantities of goods exchanged—their prices, in other words—are determined by the values individuals attach to marginal units of these goods. With a single buyer and seller, goods are exchanged as long as participants can agree on an exchange ratio that leaves each better off than he was before. In a market with many buyers and sellers, the price reflects the valuations of the buyer least willing to buy and the seller least willing to sell, what Böhm-Bawerk would call the “marginal pairs.” Regardless of the exact structure of the market, then, voluntary exchange takes place until the gains from trade are momentarily exhausted. Menger’s highly general explanation of price formation continues to form the core of Austrian microeconomics.

--Peter G. Klein, foreword to Principles of Economics, by Carl Menger (1976; repr., Auburn, AL: Ludwig von Mises Institute, 2007), 7-8.

For Carl Menger, Economics Is the Study of Purposeful Human Choice, the Relationship between Means and Ends; Menger Used Cause and Effect Unlike Jevons and Walras Who Used Simultaneous Determination

“There never lived at the same time,” wrote Ludwig von Mises, “more than a score of men whose work contributed anything essential to economics.” One of those men was Carl Menger (1840–1921), professor of political economy at the University of Vienna and founder of the Austrian School of economics. Menger’s pathbreaking Grundsätze der Volkswirtschaftslehre (Principles of economics), published in 1871, not only introduced the concept of marginal analysis, it presented a radically new approach to economic analysis, an approach that still forms the core of the Austrian theory of value and price.

Unlike his contemporaries William Stanley Jevons and Léon Walras, who independently developed their own concepts of marginal utility during the 1870s, Menger favored an approach that was deductive, teleological, and, in a primary sense, humanistic. While Menger shared his contemporaries’ preference for abstract reasoning, he was primarily interested in explaining the real-world actions of real people, not in creating artificial, stylized representations of reality. Economics, for Menger, is the study of purposeful human choice, the relationship between means and ends. “All things are subject to the law of cause and effect,” he begins his treatise. “This great principle knows no exception.” Jevons and Walras rejected cause and effect in favor of simultaneous determination, the technique of modeling complex relations as systems of simultaneous equations in which no variable “causes” another. Theirs has become the standard approach in contemporary economics, accepted by nearly all economists but the followers of Carl Menger.

--Peter G. Klein, foreword to Principles of Economics, by Carl Menger (1976; repr., Auburn, AL: Ludwig von Mises Institute, 2007), 7.