Purchasing power is the value of money measured by the amount of goods or services it can buy at a given time. When prices rise due to inflation, each dollar buys less than it used to, meaning your purchasing power declines even if your income stays the same. Conversely, purchasing power increases when prices fall or when your income grows faster than inflation.

Economists track purchasing power to understand how inflation affects everyday consumers, not just abstract price indexes. For individuals, understanding purchasing power helps explain why the same salary can feel tighter year over year, and why long-term savings and investment goals need to account for inflation to preserve real value over time.