Resources of which only a finite quantity exists, so that any constant rate of extraction must eventually cause them to run out. As the earth is of finite size, this must in principle apply to every mineral resource. In the case of some resources, such as oil, known reserves which it is economic to exploit by known techniques would run out relatively soon. The continuation of modern civilization for more than a few decades therefore depends on some combination of discoveries of new reserves, improvements in technology so that currently inaccessible reserves can be exploited, or technical progress to devise alternative fuels. In the case of some other materials such as rare metals, improvements in recycling techniques can also be hoped for. Iron ore reserves are luckily so vast that we can assume that civilization will have come to a bad end for some other reason long before they approach exhaustion.

• loanable funds
• loan-loss reserve
• loan portfolio
• lobbying
• local authority housing
• local content
• local government
• local maximum
• local minimum
• location
• lock-out
• locomotive principle
• logarithm
• 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