Let there be a positive (exogenous) probability that, at each date, the human species will disappear. We postulate an Ethical Observer (EO) who maximizes intertemporal welfare under this uncertainty, with expected-utility preferences. Various social welfare criteria entail alternative von...

Climate stabilization requires low GHG emissions. Is this consistent with nondecreasing human welfare? Our welfare index, called quality of life (QuoL), emphasizes education, knowledge, and the environment. We calibrate a multigenerational model with education, physical capital, knowledge and...

Sustainability has been largely replaced by discounted utilitarianism in contemporary climate-change economics. Our approach rejuvenates sustainability by expanding the conception of the quality of life, along the lines of the UN Human Development Reports, to include not only consumption, but...