Sustainability indicators provide information about the status of a project, policy, or community. They provide an integrated view of how well a system is functioning. Usually, sustainability indicators consider the social impact, environmental impact, and economic impact of public policy. By identifying the areas in each sector that are affected by a policy, problems can be recognized quickly and addressed.
Unlike traditional indicators, which focus on the change within a specific sector without regard to the influence of other sectors, sustainability indicators reflect the interconnected relationships of all sectors. For example, the Gross Domestic Product (GDP) is considered a traditional indicator of how well the economy is doing, but it doesn't take into account the impact of the economic activity on the environment or society. The Index of Sustainable Economic Welfare (ISEW) is considered a sustainability indicator. It subtracts from the GDP the cost of environmental damage from things like air pollution and resource depletion, while adding to the GDP economic activity such as unpaid domestic labor.
In order for a sustainability indicator to be useful, it must meet certain criteria. Sustainability indicators need to provide information that is relevant. The information must be understandable and reliable as well. Also, the data provided by sustainability indicators must be timely.
The information from sustainability indicators is typically used to identify problems that arise as a result of public policies. Solutions to the problems are generated in order to sustain progress. If the problems aren't addressed, it is believed that progress will slow down and eventually lead to social, environmental, or economic decline.
There are several economic indicators that are used to measure sustainability. The number of companies and the various sizes of companies is considered a better indicator of the job market than traditional indicators such as the unemployment rate or the number of jobs. Also, the amount of money spent in a local economy, from wages earned in the local economy, is considered a better indicator of local economic progress than GDP.
Several environmental indicators address sustainability. The amount of toxic materials produced and used is considered a better indicator of how much pollution is emitted into the environment than measuring the ambient levels of pollutants. Also, the total energy used is generally a better way to project sustainable energy consumption than the traditional indicator of the price of gasoline.
Standardized test scores are traditional indicators of social progress. The number of students that return to their local community after college is considered a better indicator of educational sustainability. Also, the number of people who actually vote in elections is a better indicator of social progress than the number of registered voters.