We evaluate several actual and hypothetical sustainable PAYGO pension structures, including: (1) versions of the US Social Security system with annual adjustments of taxes or benefits to maintain fiscal balance; (2) Sweden's Notional Defined Contribution system and several variants developed to...

Around the world, Pay-As-You-Go (PAYGO) public pension programs face serious long-term fiscal problems due primarily to actual and projected population aging, and most appear unsustainable as currently structured. Some have proposed the replacement of such plans with systems of fully funded...

Understanding the economic lifecycle -- how it varies and why -- is important in its own right, but is also critical to understanding how changes in population age structure influence many features of the macroeconomy. Economic behavior over the life cycle can be summarized by the average levels...

Intergenerational economics is characterised by three central questions: how much living generations transfer to or from future ones, how these transfers are made, and whether these transfers are sufficient to support sustainable levels of consumption for future generations. Up to now,...

What would a hypothetical one million US deaths in the Covid-19 epidemic mean for mortality of individuals at the population level? To put estimates of Covid-19 mortality into perspective, we estimate age-specific mortality for an epidemic claiming for illustrative purposes one million US lives,...

Paul Samuelson made a series of important contributions to population theory for humans and other species, evolutionary theory, and the theory of age structured life cycles in economic equilibrium and growth. The work is highly abstract but much of it was intended to illuminate issues of...

Differences in life expectancy between high and low socioeconomic groups are often large and have widened recently in many countries. Such longevity gaps affect the actuarial fairness and progressivity of public pension systems. However, behavioral responses to longevity and policy complicate...

Older Americans have experienced dramatic gains in life expectancy in recent decades, but an emerging literature reveals that these gains are accumulating mostly to those at the top of the income distribution. We explore how growing inequality in life expectancy affects lifetime benefits from...