Data collected over a period by repeated surveys of individuals or firms. Surveys may proceed by taking a fresh random sample of the population in successive periods, or by selecting a randomly chosen panel of respondents and following them over a prolonged period. Use of panel data means that more accurate and consistent data can be collected, but prolonged surveys impose a considerable burden on the informants, which may bias the membership of panels.

• logarithmic scale
• logistic curve
• log-linear function
• log-normal distribution
• log-rolling
• Lomé Convention
• London Inter Bank Offered Rate
• London International Financial Futures and Options Exchange
• long-dated security
• long position
• long rate
• long run
• long-run average cost
• long-run marginal cost
• long-run Phillips curve
• long-term interest rate
• long-term unemployment
• Lorenz curve
• loss
• loss leader
• Louvre Accord
• loyalty, brand
• Ltd
• Lucas critique
• lumpiness