Recession shapes or recovery shapes are used by economists to describe different types of recessions and their subsequent recoveries. There is no specific academic theory or classification system for recession shapes; rather the terminology is used as an informal shorthand to characterize recessions and their recoveries. The most commonly used terms are V-shaped (with variations of square-root shaped, and Nike-swoosh shaped), U-shaped, W-shaped (also known as a double-dip recession), and L-shaped recessions, with the COVID-19 pandemic leading to the K-shaped recession (also known as a two-stage recession). The names derive from the shape the economic data – particularly GDP – takes during the recession and recovery.