Which of the following methods is not typically used to assess the value of human life in cost-benefit analyses for public projects?

	Discounted value of lifetime earnings.
	Contingent valuation (asking individuals to share their perspective on the value of their life).
	Revealed preference (e.g. willingness to pay more for safety features of various products).
	Valuation based on an individual's contribution to society (e.g. valuing a doctor's life more than an unemployed homeless person's).