Principles of Economics (1890)
Marshall began his seminal work, the Principles of Economics, in 1881, and spent much of the next decade at work on the treatise. His plan for the work gradually extended to a two-volume compilation on the whole of economic thought. The first volume was published in 1890 to worldwide acclaim that established him as one of the leading economists of his time. The second volume, which was to address foreign trade, money, trade fluctuations, taxation, and collectivism, was never published.
Principles of Economics established his worldwide reputation. It appeared in 8 editions, starting at 750 pages and growing to 870 pages. It decisively shaped the teaching of economics in English-speaking countries. Its main technical contribution was a masterful analysis of the issues of elasticity, consumer surplus, increasing and diminishing returns, short and long terms, and marginal utility; many of the ideas were original with Marshall, others were improved version of ideas by W. S. Jevons and others.
In a broader sense Marshall hoped to reconcile the classical and modern theories of value. John Stuart Mill had examined the relationship between the value of commodities and their production costs, on the theory that value depends on effort expended in manufacture. Jevons and the Marginal Utility theorists had elaborated a theory of value based on the idea of maximizing utility, holding that value depends on demand. Marshall's work used both these approaches, but he focused more on costs. He noted that, in the short run, supply cannot be changed and market value depends mainly on demand. In an intermediate time period, production can be expanded by existing facilities, such as buildings and machinery; but since these do not require renewal within this intermediate period their costs (called fixed, overhead, or supplementary costs) have little influence on the sale price of the product. Marshall pointed out that it is the prime or variable costs, which constantly recur, that influence the sale price most in this period. In a still longer period, machines and buildings wear out and have to be replaced, so that the sale price of the product must be high enough to cover such replacement costs. This classification of costs into fixed and variable and the emphasis given to the element of time probably represent one of Marshall's chief contributions to economic theory. He was committed to partial equilibrium models over general equilibrium on the grounds that the inherently dynamical nature of economics made the former more practically useful.
Much of the success of Marshall's teaching and Principles book derived from his effective use of diagrams, which were soon emulated by other teachers worldwide.
Alfred Marshall was the first to develop the standard supply and demand graph demonstrating a number of fundamentals regarding supply and demand including the supply and demand curves, market equilibrium, the relationship between quantity and price in regards to supply and demand, law of marginal utility, law diminishing returns, and the ideas of consumer and producer surpluses. This model is now used by economists in various forms using different variables to demonstrate several other economic principles. Marshall's model allowed a visual representation of complex economic fundamentals where before all the ideas and theories were only capable of being explained through words. These models are now critical throughout the study of economics because it allows a clear and concise representation of the fundamentals or theories being explained.
Read more about this topic: Alfred Marshall