Sunk costs play a central role in antitrust economics, but are often misunderstood and mismeasured. I will try to clarify some of the conceptual and empirical issues related to sunk costs, and explain their implications for antitrust analysis. I will be particularly concerned with the role of...

The regulation of telecommunications, railroads, and other network industries has been based on mandatory unbundling and facilities sharing - entrants have the option to lease part or all of incumbents' facilities if and when they desire, at rates determined by regulators. This flexibility is of...

This paper addresses the impact on investment incentives of the network sharing arrangements mandated by the Telecommunications Act of 1996, with a focus on the implications of irreversible investment. Although the goal is to promote competition, the sharing rules now in place reduce incentives...

An estimate of the social cost of carbon (SCC) is key to climate policy. But how should we estimate the SCC? A common approach is to use an integrated assessment model (IAM) to simulate time paths for the atmospheric CO2 concentration, its impact on global mean temperature, and the resulting...

In recent articles, I have argued that integrated assessment models (IAMs) have flaws that make them close to useless as tools for policy analysis. IAM-based analyses of climate policy create a perception of knowledge and precision that is illusory, and can fool policy-makers into thinking that...

Very little. A plethora of integrated assessment models (IAMs) have been constructed and used to estimate the social cost of carbon (SCC) and evaluate alternative abatement policies. These models have crucial flaws that make them close to useless as tools for policy analysis: certain inputs...

I examine the risk/return tradeoff for environmental investments, and its implications for policy choice. Consider a policy to reduce carbon emissions. To what extent does the value of such a policy depend on the expected future damages from global warming versus uncertainty over those damages,...

Climate policy poses a dilemma for environmental economists. The economic argument for stringent GHG abatement is far from clear. There is disagreement among both climate scientists and economists over the likelihood of alternative climate outcomes, over the nature and extent of the uncertainty...

Climate policy is complicated by the considerable compounded uncertainties over the costs and benefits of abatement. We don't even know the probability distributions for future temperatures and impacts, making cost-benefit analysis based on expected values challenging to say the least. There are...

Any economic analysis of climate change policy requires some model that describes the impact of warming on future GDP and consumption. Most integrated assessment models (IAMs) relate temperature to the level of real GDP and consumption, but there are theoretical and empirical reasons to expect...