In economics, microeconomics is also commonly referred to by which one of the following alternative names?

Introduction / Context:
Microeconomics studies the behaviour of individual consumers and firms and the determination of prices and quantities in specific markets. Because of this focus on price determination, microeconomics is sometimes given another descriptive name. This question tests whether you remember that alternative name.

Given Data / Assumptions:
- The subject under discussion is microeconomics.
- Four possible alternative names are listed: profit theory, loss theory, price theory and expenditure theory.
- You must pick the term that is widely used in textbooks as another name for microeconomics.

Concept / Approach:
Microeconomics is concerned with how prices of goods and services, as well as factor prices like wages and interest, are determined in individual markets. It explains how demand and supply interact to determine equilibrium prices and quantities, and how these prices guide resource allocation. For this reason, microeconomics is often called price theory. The other terms listed are not standard names for the subject.

Step-by-Step Solution:
Step 1: Consider profit theory. While profits are one topic studied within microeconomics, the entire subject is not limited to profits and this phrase is not used as a standard name for microeconomics.Step 2: Consider loss theory. This term is not commonly used in economics and certainly is not a label for microeconomics.Step 3: Consider price theory. Many textbooks explicitly describe microeconomics as price theory because it focuses on how prices emerge in markets and how they affect resource allocation and welfare.Step 4: Consider expenditure theory. Expenditure is only one aspect of economic analysis and again is not a recognised synonym for microeconomics.

Verification / Alternative check:
You can quickly verify by thinking of chapter titles in microeconomics books: demand, supply, price determination, elasticity, consumer choice, theory of the firm and pricing of factors all revolve around prices. In contrast, macroeconomics is often described as income and employment theory, focusing on aggregate output and jobs. This contrast reinforces that microeconomics is best associated with price theory.

Why Other Options Are Wrong:
Profit theory is wrong because it is just one part of microeconomic analysis, not the whole field. Loss theory is wrong because it is not a recognised term. Expenditure theory is wrong because it does not capture the central role of price determination that characterises microeconomics.

Common Pitfalls:
Some students focus on firm behaviour and immediately think of profit maximisation, which may tempt them to choose profit theory. Others see expenditure and confuse it with consumer behaviour. However, the most comprehensive and widely used alternative name is price theory, so that is the safe and correct choice.

Final Answer:
Microeconomics is also called Price theory.