Appropriation Externality (Hackett, 1998, chapters 5 and 15). Occurs when the act of harvesting resource units, usually from a common-pool resource, results in damage to the future productive capacity of the resource that negatively affects other appropriators (resource users).

Biological Reference Point (King, 1995). A particular value of stock size, catch, fishing effort and fishing mortality which may be used as a goal in fisheries management.

Capital Stuffing (Allen, 1999). Capital stuffing occurs when a fishery management plan attempts to control catches through a limit on certain inputs (days at sea, traps, etc.) and fishing businesses attempt to maintain their catch by utilizing more capital, such as bigger, more powerful equipment or more sophisticated electronics. See also the listing for "input stuffing or input substitution," below.

Catchability coefficient (q) (King, 1995). The proportion of the total stock caught by one unit of fishing effort.

Coase Theorem (Hackett, 1998, chapter 6). Named after economist Ronald Coase, the Coase theorem starts from the premise that a complete set of private property rights can be assigned to aspects of the environment, that polluters and those harmed by pollution can negotiate at very low cost, and that "free rider" effects among multiple parties on either side of the negotiation are minimal. Under these conditions the central finding is that private parties can negotiate a solution equally as efficient as that which would result from more centralized regulatory processes using benefit/cost analysis.

Co-management (cooperative management) (King, 1995). Either informal or legal arrangements between government representatives, community groups and other user groups, to take responsibility for, and manage, a fishery resource and/or its environment on a cooperative basis.

Common-Pool Resource (Hackett, 1998, chapters 5, 7, and 15). Those resources such as groundwater basins, rivers, marine fisheries, and community forests for which (1) it is difficult to exclude multiple people from appropriating from the resource, and (2) the resource units appropriated by one are no longer available to others. Contrast with private goods and pure public goods.

Common Property Rights (Hackett, 1998, chapter 4). The bundle of rights that includes access, withdrawal (use of resource units), management (how and when the resource is accessed or maintenance is performed or use is monitored), and exclusion (determining who can and cannot access or use the resource). Those who hold these rights are sometimes known as "proprietors," and management and alienation (sale of the resource) rights are usually exercised in a collective-choic context along with other proprietors.

Consumer Surplus (Hackett, 1998, chapter 3). When a buyer's willingness to pay value exceeds the price the buyer had to pay, that difference is known as consumer surplus.

Decentralized Markets (Hackett, 1998, chapter 3). When resource allocation occurs as a consequence of a set of individual market transactions rather than centralized allocation decisions made by government. Decentralized markets are a key element of capitalist systems.

Demand Curve (Hackett, 1998, chapter 3). A graphical representation of the inverse relationship between price and quantity demanded. Points along a demand curve represent buyer willingness-to-pay values.

Density (King, 1995). The numbers or weight of organisms per unit area or volume. (The biological characteristics of natural populations such as fish stocks often vary with the density of the animals. The growth of an animal, or for the population as a whole, for example, may be "density-dependent." That is, the stock may grow slower when the density of animals is high than when it is low.)

Discount Rate (Hackett, 1998, chapters 5, 6, and 12). The rate at which the present value of a benefit to be received in the future shrinks as the time lag increases. Discount rates are embodied in interest rates charged on borrowed money and other financial investments in financial markets. (A common manifestation of how people value money today compared to money in the future is the failure of many people to set aside a small amount of money in the present, even though they know it will grow into a large amount of money for future uses such as retirement. In effect, they discount those future benefits at a higher rate than the interest that they expect on their savings.)

Dynamic Efficiency (Hackett, 1998, chapter 5). A criterion for evaluating projects or decisions that generate a stream of benefits and/or costs into the future. When a set of alternatives is being considered, the dynamically efficient alternative generates the largest present discounted value of net benefits, profits, or surplus.

Economic Rationality (Hackett, 1998, chapter 1). When a choice is taken from among competing options that yields anticipated net benefits that exceed the opportunity cost (see opportunity cost below).

Economics (Hackett, 1998, chapter 1). The study of how scarce resources are allocated among competing uses.

Efficiency (Hackett, 1998, chapters 3 and 6). Generally refers to the condition of minimal waste. In markets the condition that exists when all the available gains from trade are realized (efficient resource allocation) or when goods are made at minimum cost (efficient production). A proposed social policy is Pareto-efficient compared to the status quo when it makes some people better off and nobody worse off. In contrast, a proposed social policy is potentially Pareto-efficient (or Kaldor-Hicks-efficient) compared to the status quo when it generates net social benefits that could potentially be used to compensate those made worse off.

Egg Production Per Recruit (Allen, 1999). The term egg production per recruit is used in the official definition of overfishing for the lobster fishery. The definition states that the fishery shall be managed so as to obtain 10% of the egg production per recruit compared to an unfished population. This means that before the average young female (recruit) is caught, she should be given a chance to produce 10% of the eggs that she would if she were allowed to live her natural life.

Externality (Hackett, 1998, chapter 4). Positive externalities are unpaid-for benefits enjoyed by others in society as a consequence of a buyer/seller transaction. For example, when parents pay to vaccinate their children against infectious disease, they create an external benefit -- the reduced likelihood of epidemic -- that is shared by many in society. Negative externalities are uncompensated costs borne by others in society as a consequence of a buyer/seller transaction. For example, when firms can avoid costly cleanup by polluting, they create an external cost -- the harms created by their pollution -- that is shared by many in society.

F 0.1 (King, 1995). A reference point based on the value of fishing mortality, F, at which the slope of the yield per recruit curve is 0.1 (10 per cent) of its initial value; regarded as a conservative level of exploitation which allows for economic viability and a buffer against recruitment overfishing.

F 10% epr (Allen, 1999). The level of fishing mortality, F, at which an average female in the population will produce 10 per cent of the eggs that would be produced by a female that was left to live her natural life span (that is, unfished).

F max (Allen, 1999). The level of fishing mortality, F, at which a stock will produce the maximum sustained yield (MSY).

Fishery Dependent Data (Allen, 1999). Fishery dependent data consists of catch reports, sea sampling, and other data about the resource and the fishery that is obtained from the fishery. There are a number of potential problems with fishery dependent data, such as mis-reporting, differences in the fishery over time caused by changes in markets, prices, gear changes, etc. For example, an expansion of a fishery on to new grounds may indicate that catch per unit effort has increased, which is usually a sign that abundance is increasing. Improved gear may produce a similar result.

Fishery Independent Data (Allen, 1999). Fishery independent data is obtained from research surveys. Research surveys are designed to be consistent over time. This is intended to give a picture of the resource that is not affected by changing fishing effort, changing fishing gear, or faulty reporting of catches. For example, an index of abundance of sub-legal lobsters taken from commercial lobster traps would be affected by changes in the legal escape vent size. A research survey that was intended to obtain a sub-legal lobster abundance index would use the same traps over time.

Fishing Mortality Rate (Allen, 1999). The fishing mortality rate describes how fast animals are removed from a population. It is related to the percentage of the animals that are removed by fishing each year, but is not identical to that percentage, because it is what is called an instantaneous rate. A change in the fishing mortality rate does not produce an identical change in the landings. Over time, lower fishing mortality rates can actually result in higher landings. Thus, the common perception that a 50 percent reduction in the fishing mortality rate will result in a 50 percent reduction in landings is not correct when fishing mortality rates are at high levels. Fishing mortality rates commonly range from 0 (no fishing) to F=2.???. Fishing mortality rates greater than 1.0 are considered very high.

Fixed Costs (Hackett, 1998, chapter 6). Those costs that do not vary with the amount a firm produces in the short run. An example is the cost of leasing office space or renting equipment (or owning a boat and traps).

Free Rider (Hackett, 1998, chapters 3 and 6). One who enjoys the benefits of a public good or common-pool resource without paying a share of the costs of providing for or maintaining it.

Fugitive Resources (Hackett, 1998, chapters 4 and 5). Those resources such as marine fisheries, groundwater basins, or stocks of fresh air having the characteristic of being difficult or impossible to partition. Such resources tend to be held as common property rather than private property.

Gain from Trade (Hackett, 1998, chapters 3, 4, and 6). The positive net benefit to market participants that occurs as a consequence of trade. The gain to consumers, known as consumer surplus, is the difference between the maximum amount that consumers were willing to pay (consumer valuation) and actual market price. The gain to producers, known as producer surplus, is the difference between the minimum amount that sellers are willing to accept (producer valuation) and actual market price. Gains from trade aggregated across all market participants are known as total surplus.

Growth Overfishing (King, 1995). A level of fishing in which young recruits entering the fishery are caught before they grow to an optimum marketable size; a level beyond that required to maximize yield (or value) per recruit.

Individual Transferable Effort Quota (ITEQ) (Allen, 1999). A limit on fishing effort allocated to an individual fisher, who can either use that effort himself, or transfer it to someone else through sale or lease. (ITEQs are comparable to the marketable pollution allowance systems defined below.)

Individual Transferable Quota (ITQ) (King, 1995). A catch limit or quota allocated to an individual fisher, who then has a guaranteed share (which may be either harvested or traded) of the Total Allowable Catch of a particular resource species. (ITQs are comparable to the marketable pollution allowance systems defined below.)

Input Controls (King, 1995). Limitations on the amount of fishing effort; restrictions on the number, type and size of fishing vessels or fishing gear, or on the fishing areas or times in a fishery.

Input Stuffing (or Input Substitution) (Allen, 1999). Whereas a fishing business uses various factors of production (inputs) to produce a certain level of catch, a management plan that attempts to limit the catch by controlling certain inputs but not others may fail because fishing businesses substitute more of the uncontrolled inputs for the controlled inputs in an attempt to maintain their catch.

Invisible Hand (Hackett, 1998, chapters 5 and 7). A term associated with economics pioneer Adam Smith that refers to the efficient way that well-functioning competitive markets coordinate the complex and interdependent allocation of scarce resources in an economy without the guiding hand of economic planners.

Marginal Cost (Hackett, 1998, chapter 4). The increase in total cost that occurs as a consequence of a small (one-unit) increase in production output. (Economists expect that a rational, profit maximizing business decision-maker will expand production until marginal cost equals the price that he receives for that last unit of production.)

Marketable Pollution Allowance Systems (Hackett, 1998, chapter 9). These systems are designed to work in conjunction with overall emissions-control schemes, with the objective being to reduce the cost of compliance. Polluters are issued quotas (usually a fraction of historical emissions levels), which represent their total emissions allowance under the emissions-control scheme. If some firms can further reduce their emissions, and if their cost of emissions control is much lower than for others, then trade in allowances will result in the firms with lower emissions-control costs selling allowances to firms with higher emissions-control costs. Trade in pollution allowances shifts cleanup to firms with lower cleanup costs, reducing the industry-wide cost of compliance with an overall emissions reduction target.

Market Capitalism (Hackett, 1998, chapter 3). A socioeconomic system based on the use of a complete set of decentralized markets to allocate scarce resources, goods, and services. In this system human-made capital is privately owned by individuals, and production and employment decisions are decentralized and thus made by firms. Contrast with centrally planned allocation of scarce resources and government (or community) ownership of human-made capital under socialism or communism.

Market Failures (Hackett, 1998, chapter 3). Occur when any of the conditions required for a well-functioning competitive market are not met. Examples include monopolization or cartelization of markets, the presence of significant positive or negative externalities, or poorly informed buyers.

Maximum Economic Yield (MEY) (King, 1995). The yield above which the revenue generated by a marginal increase in effort is less than the cost of that increase; the point at which profits earned in excess of those needed to cover all fishing costs is maximized.

Maximum Sustainable Yield (MSY) (King, 1995). The largest annual catch that may be taken from a stock continuously without affecting the catch of future years; a constant long-term MSY is not a reality in most fisheries, where stock sizes vary with the strength of year classes moving through the fishery.

Natural Capital (Hackett, 1998, chapters 11 and 13). Generates the flow of natural resources and other environmental and ecological benefits. Includes both the components and the structural relationships in the earth's ecosystems, the integrity of which is essential for life on earth.