Here are the major components of GPI and a web site with additional information: http://www.cyberus.ca/~sustain1/Question/GPI.html
I. Crime & family breakdown
Social breakdown imposes large economic costs on individuals and society, in the form of legal fees, medical expenses, damage to property, and the like. The GDP treats such expenses as additions to well-being. By contrast, the GPI subtracts the costs arising from crime and divorce.
II. Household & volunteer work.
Much of the most important work in society is done in household and community settings: childcare, home repairs, volunteer work, and the like. These contributions are ignored in the GDP because no money changes hands. To correct this omission, the GPI includes, among other things, the value of household work figured at the approximate cost of hiring someone to do it.
III. Income distribution.
A rising tide does not necessarily lift all boats -- not if the gap between the very rich and everyone else increases. Both economic theory and common sense tell us that the poor benefit more from a given increase in their income than do the rich. Accordingly, the GPI rises when the poor receive a larger percentage of national income, and falls when their share decreases.
IV. Resource depletion.
If today's economic activity depletes the physical resource base available for tomorrow's, then it is not really creating well-being; rather, it is just borrowing it from future generations. The GDP counts such borrowing as current income. The GPI, by contrast, counts the depletion or degradation of wetlands, farmland, and non-renewable minerals (including, oil) as a current cost.
V. Pollution.
The GDP often counts pollution as a double gain; once when it's created, and then again when it is cleaned up. By contrast, the GPI subtracts the costs of air and water pollution as measured by actual damage to human health and the environment.
VI. Long-term environmental damage.
Climate change and the management of nuclear wastes are two long-term costs arising from the use of fossil fuels and atomic energy. These costs do not show up in ordinary economic accounts. The same is true of the depletion of stratospheric ozone arising from the use of chlorofluorocarbons. For this reason, the GPI treats as costs the consumption of certain forms of energy and of ozone-depleting chemicals.
VII. Changes in leisure time.
As a nation increases in wealth, people should have increasing latitude to choose between more work and more free time for family or other activities. In recent years, however, the opposite has occurred. The GDP ignores this loss of free time, but the GPI treats leisure as most Americans do -- as something of value. When leisure time increases, the GPI goes up; when Americans have less of it, the GPI goes down.
VIII. Defensive expenditures.
The GDP counts as additions to well-being the money people spend just to prevent erosion in their quality of life or to compensate for misfortunes of various kinds. Examples are the medical and repair bills from automobile accidents, commuting costs, and household expenditures on pollution control devices such as water filters. The GPI counts such "defensive" expenditures as most Americans do: as costs rather than as benefits.
IX. Life span of consumer durables & public infrastructure.
The GDP confuses the value provided by major consumer purchases (e.g., home appliances) with the amounts Americans spend to buy them. This hides the loss in well- being that results when products are made to wear out quickly. To overcome this, the GPI treats the money spent on capital items as a cost, and the value of the service they provide year after year as a benefit. This applies both to private capital items and to public infrastructure, such as highways.
X. Dependence on foreign assets.
If a nation allows its capital stock to decline, or if it finances its consumption out of borrowed capital, it is living beyond its means. The GPI counts net additions to the capital stock as contributions to well-being, and treats money borrowed from abroad as reductions. If the borrowed money is used for investment, the negative effects are canceled out. But if the borrowed money is used to finance consumption, the GPI declines.