Which of these is a significant indicator of economic performance?

Gross domestic product (GDP) is a crucial indicator of economic performance as it measures the total value of all goods and services produced over a specific time period within a country's borders. It provides an essential snapshot of economic health, reflecting the size and growth rate of an economy. An increase in GDP indicates that an economy is growing, suggesting higher production levels and greater spending by consumers and businesses, which can lead to more job creation and improved living standards.

In contrast, while interest rates influence economic activities by affecting borrowing costs and spending, they are not direct measures of performance. Tax policies can also impact economic activity by influencing consumer behavior and investment decisions but, like interest rates, they do not directly measure output. Market sentiment reflects investor attitudes and expectations and can influence market prices, but it is inherently subjective and does not provide a quantifiable measure of actual economic performance. Thus, GDP stands out as the most direct and comprehensive economic performance indicator among the given options.