A "multiplier" is a mathematical term that refers to a number used to increase another number. In simple terms, when you multiply two numbers, one of them is the multiplier. For example, in the equation 3 × 4 = 12, the number 3 is the multiplier, which increases 4 to reach 12. In economics, the term "multiplier effect" describes how an initial amount of spending leads to increased economic activity. For instance, when the government invests in infrastructure, it creates jobs, which in turn increases consumer spending, further boosting the economy. This concept is often associated with John Maynard Keynes, who emphasized its importance in economic theory.