The external economy available to individuals or firms in large concentrations of population and economic activity. These arise because larger markets allow wider choice and a greater range of specialist services. Agglomeration economies are believed to explain the tendency of conurbations to contain an increasing share of the population of many countries. Beyond some point further agglomeration gives rise to diseconomies due to congestion and pollution.

• 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
• lump of labour
• lump-sum tax