tic (available only as a fixed amount), such as land. It is also called "pure economic rent." See also Hotelling rent.

Restoration costs:

Actual and imputed expenditures for activities aimed at the restoration of depleted or degraded natural systems, partly or completely counteracting the (accumulated) environmental impacts of economic activities. See also environmental restoration .

Ricardian rent:

Any return to a factor of production fixed in supply.

Rio Declaration on Environment and Development:

See United Nations Conference on Environment and Development (United Nations, 1993).

Risk assessment:

Quantitative and qualitative evaluation of the risk posed to human health and/or the environment by the actual or potential presence of and exposure to particular pollutants.

Risk management:

Process of evaluating and selecting among alternative regulatory and nonregulatory responses to risk. The selection process necessarily requires consideration of legal, economic, and social factors.


Payment for the use of assets, both intangible, such as patents, and tangible, notably subsoil assets. Royalties paid for the use of subsoil assets are also called rents even though they are not rents by the definition given above.


Satellite accounts:

Additional or parallel accounting system that expands the analytical capacity of national accounts without overburdening or disrupting the central system. It may provide additional information, apply complementary or alternative concepts, extend the coverage of costs and benefits of human activities, and link physical with monetary data. The System of Integrated Environmental and Economic Accounting (SEEA) constitutes a satellite system of the System of National Accounts (SNA).

Secondary air pollution:

Pollution caused by reactions in air already polluted by primary emissions (from factories, automobiles, and so forth). An example of secondary air pollution is photochemical smog.

Secondary treatment:

Second step in most waste treatment systems, during which bacteria consume the organic portions of the wastes. This is accomplished by bringing the sewage, bacteria, and oxygen together in trickling filters or within an activated sludge process. Secondary treatment removes all floating and settleable solids and about 90 percent of oxygen-demanding substances and suspended solids. Disinfection by chlorination is the final stage of the secondary treatment process.


See System of Integrated Environmental and Economic Accounting .


See System of National Accounts.

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement