Are We Consuming Too Much?
提出两个标准（跨期效用最大化和可持续性）来判断当前消费是否过度，并给出考虑人口增长和技术进步的可持续性公式，发现部分贫困地区因自然资本消耗未被补偿而不可持续。
This paper articulates and applies frameworks for examining whether consumption is excessive. We consider two criteria for the possible excessiveness (or insufficiency) of current consumption. One is an intertemporal utility-maximization criterion: actual current consumption is deemed excessive if it is higher than the level of current consumption on the consumption path that maximizes the present discounted value of utility. The other is a sustainability criterion, which requires that current consumption be consistent with non-declining living standards over time. We extend previous theoretical approaches by offering a formula for the sustainability criterion that accounts for population growth and technological change. In applying this formula, we find that some poor regions of the world are failing to meet the sustainability criterion: in these regions, genuine wealth per capita is falling as investments in human and manufactured capital are not sufficient to offset the depletion of natural capital.