Microeconomics vs Macroeconomics: What's the Difference

What microeconomics studies

According to Treccani, microeconomics is the branch of economic theory that deals with the behavior of individual economic agents: consumers and firms, both when they act on their own and when they interact with each other, typically through the market. Its field of view covers the allocation of goods among households, firms, individual industries and specific markets.

In practical terms, microeconomics answers questions like: why does the price of a good rise when demand grows? How does a firm decide how much to produce? What happens to a market when a new competitor enters?

Practical example: a grocery store raises the price of strawberries once the season ends and supply shrinks; shoppers buy fewer of them, and some switch to other fruit. It’s a textbook case of microeconomics: one market, one good, supply and demand adjusting to each other.

Microeconomics is traditionally traced back to Léon Walras, in the early 1870s. Treccani notes that before then, and for several decades afterward under the classical and neoclassical schools, economists’ attention remained focused on individual-level phenomena: what we now call the microeconomic view was, quite simply, the only view available.

What macroeconomics studies

Macroeconomics, Treccani continues, is concerned with identifying the equilibrium values of the large aggregates: national income, overall employment, the general price level. Among the variables it analyzes are also aggregate demand (public and private consumption, investment, the trade balance), monetary and fiscal policy, unemployment and inflation.

The historical reference point that encyclopedias cite for the birth of the discipline is the General Theory of Employment, Interest and Money, published by John Maynard Keynes in 1936. With that book, according to Treccani, the state took on “a decisive role” in supporting economic growth through public spending, an effect textbooks call the income multiplier: public spending generates an increase in national income that is more than proportional to the initial outlay. According to Treccani, this same moment also marks the birth of economic policy as its own scientific discipline, dedicated to studying the effects of state intervention.

A Recap on inflation or one on GDP are, in this sense, direct examples of macroeconomic topics: they describe an entire country or currency area, not a single store or a single product.

When the two disciplines split

Almost seventy years separate the founding of microeconomics (early 1870s) from the birth of macroeconomics as a distinct discipline (1936). According to Treccani, the shift wasn’t sudden: it was specifically the Keynesian literature of the interwar years that gradually pushed the analysis of individual-level processes aside in favor of the large aggregates. Before Keynes, other economists, from Quesnay to Malthus, from Say to Marx, had already touched on topics we would now call macroeconomic, but without building a separate discipline around them, with its own name and its own method.

Historically, microeconomics remains the one that took shape as an independent field of study first.

Micro and macro economics: how they connect in practice

Large macroeconomic quantities don’t exist in the abstract: Treccani says as much when it describes aggregates as sets built from countless individual quantities. National income is the sum of what millions of households and firms earn; overall employment is the sum of individual hires; inflation tracks how the prices of thousands of goods and services, set every day in individual markets, change on average.

The link runs the other way too: a decision made at the macroeconomic level reshapes the choices of individual agents. When a central bank raises interest rates, a mortgage becomes more expensive: households put off buying a home, firms rethink an investment plan.

A recession, for instance, is a phenomenon observed at the macroeconomic level, a country’s GDP contracting for at least two consecutive quarters, but its causes and effects almost always run through microeconomic choices: firms cutting output, households trimming spending, a labor market hiring less. A recession, then, lines up both levels at once: individual stores and households on one side, a country’s GDP on the other.