The value of life is an economic or moral value assigned to life in general, or to specific living organisms. In social and political sciences, it is the marginal cost of death prevention in a certain class of circumstances. As such, it is a statistical term, the cost of reducing the (average) number of deaths by one. It is an important issue in a wide range of disciplines including economics, health care, political economy, insurance, worker safety, environmental impact assessment, and globalization. Discussions about the value of life would be more-or-less limited to university philosophy departments and religious groups if it were not for the fact that this value must be calculated in an exact quantitative way by practitioners in these disciplines.
When deciding on the appropriate level of health care spending, a typical method is to equate the marginal cost of the health care to the marginal benefits received. In order to obtain a marginal benefit amount, some estimation of the dollar value of life is required.
In biosafety, workplace safety, and insurance, it is also necessary to put a precise economic value on a given life. There can be no such thing as a perfectly safe or risk free system - one can always make a system safer by spending more money. However, there are diminishing returns involved. In travel, the economic value of life, for safety purposes, varies between around $1,000,000 for trains, and around $20,000 for automobiles.
Opponents of abortion place a high moral value on individual fetus lives, often (but not always) to the point that they consider this value to overwhelm any right to choose that a woman may have. Some economists consider this debate to be an example of a market failure. Because no market has developed where a woman can trade her right to choose for the unborn child's right to life, the market is unable to assign financial value to either proposition.
There are also intergenerational aspects to the value of life. Economists calculate social discount rates based on the interest rates prevalent in financial markets. The higher the social discount rate, the more future generations are devalued relative to the current generation.
The anti-globalization movement objects to the obvious disparity between the value assigned to life in developed nations versus developing nations - most particularly as reflected in World Bank, WTO, and IMF decisions. They point to such numbers as the IPCC assumption that a developed nation can pay fifteen times more than a developing nation to avert a death due to climate change, as evidence of systematic neglect of the value of life in the poorer South, as opposed to the more developed North. Some also fear that more standard global value of life mechanisms could have consequences for the working people in the developed nations.
A few also debate as to whether animal life deserves to have a value assigned to it, such as in the field of biodiversity. A moral argument associated with this is the great ape genocide debate, which has become especially poignant since the recent advocacy by some scientists to move the two chimpanzee species into the genus Homo (previously it was considered a hominid).
Some advocates feel that putting an economic price tag on life is "inhumane", because every life is "priceless". However, with a limited supply of resources or infrastructural capital (e.g. ambulances), or skill at hand, it is impossible to save every life, so some trade off must be made. Also, this argumentation neglects the statistical context of the term. It is not commonly attached to lives of individuals or used to compare the value of one persons life relative to another persons. It is mainly used in circumstances of saving lives as opposed to taking or "producing" lives.
Refusal to assign any value to life often leads, ironically, to no value being attached to life. So, treating an endangered human life, or even the value of Earth itself, in economics formally as a commodity can be morally justified, in that risks of failure to protect it, thus become costs.