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...

The case for progressive income taxation is often based on the classic result of Jakobsson (1976) and Fellman (1976), according to which progressive and only progressive income taxes - in the sense of increasing average tax rates on income-ensure a reduction in income inequality. This result has...

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...

The case for progressive income taxation is often based on the classic result of Jakobsson (1976) and Fellman (1976), according to which progressive and only progressive income taxes - in the sense of increasing average tax rates on income - ensure a reduction in income inequality. This result...

Whether or not to vaccinate one's child is a decision that a parent may approach in several ways. The vaccination game, in which parents must choose whether to vaccinate a child against a disease, is one with positive externalities (herd immunity). In some societies, not vaccinating is an...

The case for progressive income taxation is often based on the classic result of Jakobsson (1976) and Fellman (1976), according to which progressive and only progressive income taxes - in the sense of increasing average tax rates on income - ensure a reduction in income inequality. This result...