journal articles

Thomas Ash, Antonio M. Bento, Daniel Kaffine, Akhil Rao, Ana I. Bento Disease-economy trade-offs under alternative epidemic control strategies in Nature Communications

Abstract: Public policy and academic debates regarding pandemic control strategies note disease-economy trade-offs, often prioritizing one outcome over the other. Using a calibrated, coupled epi-economic model of individual behavior embedded within the broader economy during a novel epidemic, we show that targeted isolation strategies can avert up to 91% of economic losses relative to voluntary isolation strategies. Unlike widely-used blanket lockdowns, economic savings of targeted isolation do not impose additional disease burdens, avoiding disease-economy trade-offs. Targeted isolation achieves this by addressing the fundamental coordination failure between infectious and susceptible individuals that drives the recession. Importantly, we show testing and compliance frictions can erode some of the gains from targeted isolation, but improving test quality unlocks the majority of the benefits of targeted isolation.

Akhil Rao, Matthew Burgess, Daniel Kaffine: Orbital-use fees could more than quadruple the value of the space industry in Proceedings of the National Academy of Sciences

Abstract: The space industry‚Äôs rapid recent growth represents the latest Tragedy of the Commons. Satellites launched into orbit contribute to—and risk damage from—a growing buildup of space debris and other satellites. Collision risk from this orbital congestion is costly to satellite operators. Technological and managerial solutions—such as active debris removal or end-of-life satellite deorbit guidelines—are currently being explored by regulatory authorities. However, none of these approaches address the underlying incentive problem: satellite operators do not account for costs they impose on each other via collision risk. Here, we show an internationally harmonized orbital-use fee can correct these incentives and substantially increase the value of the space industry. We construct and analyze a coupled physical-economic model of commercial launches and debris accumulation in low-Earth orbit. Similar to carbon taxes, our model projects an optimal fee that rises at a rate of 14% per year, equal to roughly $235,000 per satellite-year in 2040. The long-run value of the satellite industry would more than quadruple by 2040—increasing from around $600 billion under business-as-usual to around $3 trillion. In contrast, we project purely technological solutions are unlikely to fully address the problem of orbital congestion. Indeed, we find debris removal sometimes worsens economic damages from congestion by increasing launch incentives. In other sectors, addressing the Tragedy of the Commons has often been a game of catch-up with substantial social costs. The infant space industry can avert these costs before they escalate.

working papers

Akhil Rao, Giacomo Rondina: Open access to orbit and runaway space debris growth draft (Under review at the Journal of the Association of Environmental and Resource Economists)

Abstract: As Earth's orbital space fills with satellites and debris, debris-producing collisions between orbiting bodies become more likely. Runaway space debris growth, known as Kessler Syndrome, may render Earth's orbits unusable for centuries. We present a dynamic physico-economic model of Earth orbit use under rational expectations with endogenous collision risk and Kessler Syndrome. When satellites can be destroyed in collisions with debris and other satellites, there is a manifold of open-access equilibria rather than a unique equilibrium. When debris can collide to produce more debris, this manifold allows Kessler Syndrome to occur along equilibrium paths. We show open access is increasingly and inefficiently likely to cause Kessler Syndrome as satellites become more profitable, highlighting the need for orbital-use management.

Economic Principles of Space Traffic Control (job market paper) draft

Abstract: Open access to Earth's orbits presents a unique regulatory challenge. In this paper, I derive economic principles governing the choice of space traffic control policies. I show that policies which target satellite ownership, such as satellite taxes or permits, achieve greater expected social welfare than policies which target satellite launches, such as launch taxes or permits. Price or quantity policies can achieve equal expected social welfare due to the symmetry of uncertainty between regulators and firms. I also show that active debris removal can reduce the risk of runaway debris growth no matter how it is financed, but can only reduce the risk of satellite-destroying collisions if satellite owners pay for it or if competition from removal--induced entry reduces the returns to satellite ownership. Technical solutions to space traffic control tend to emphasize launch restrictions or public funding of debris removal technology development and use, but often ignore that current and prospective orbit users dissipate rents under open access. While satellite-focused policies can achieve first-best orbit use, attempts to control orbital debris growth and collision risk through launch fees or debris removal subsidies under open access may be ineffective or backfire.

International cooperation and competition in orbit-use management (with Aditya Jain) draft

Abstract: Orbit-use management efforts can be structured as binding national regulatory policies or as self-enforcing international treaties. New treaties to control space debris growth appear unlikely in the near future. Spacefaring nations can pursue national regulatory policies, though regulatory competition and open access to orbit make their effectiveness unclear. We develop a game-theoretic model of national regulatory policies and self-enforcing international treaties for orbit-use management in the face of open access, regulatory competition, and catastrophe. While open access limits the effectiveness of national policies, market-access control ensures the policies can improve environmental quality. A large enough stock of legacy debris ensures existence of a global regulatory equilibrium where all nations choose to levy environmental regulations on all satellites. The global regulatory equilibrium supports a self-enforcing treaty to avert catastrophe by making it costlier to leave the treaty and free ride.

The Economics of Orbital Transportation draft

Abstract: Transportation through outer space involves a sequence of transfer orbits to move a payload from origin to destination. Transfer orbits are often chosen with the goal of minimizing either the energy required or time taken for the trip. Commercial shippers will instead choose transfer orbits to maximize delivery profits. When payment is received upon delivery and the opportunity cost of funds is positive, profit-maximizing transfer orbits may minimize neither trip energy nor time. Such ``interior transfer orbits'' balance the marginal present value from quicker delivery against the marginal cost of energy expenditures to reduce delivery time.

Elicitation and Corrective Taxation (with Brennan McConnell) (mimeo)

Abstract: Marginal contributions to observable aggregate stocks are often unobservable in games with negative stock externalities, making optimal corrective taxation a difficult endeavor. We propose a new class of mechanism, the elicited tax, for such settings. The elicited tax uses an observable aggregate measure to elicit private information about marginal contributions, and a scored tax to penalize reports which are inconsistent with the observable aggregate and other reports. In this paper, we define a notion of strict propriety for elicited taxes, show that under perfect competition reports are Nash equilibria if and only if they are consistent with the observable aggregate, and that strictly proper elicited taxes ensure socially optimal output and externality production. We then study a particular strictly proper elicited tax, the Brier-Pigou tax, which combines a modified Brier scoring rule with a Pigouvian tax. Numerical experiments highlight three properties of the Brier-Pigou tax: (1) the tax can maximize social welfare when firms are perfectly competitive; (2) the tax achieves close to optimal welfare even when firms are perfectly collusive reporters; and (3) the proportion of consistent lies which are risk-dominated by truthful reporting for each firm depends on the number of firms providing reports and that firm's true marginal externality, suggesting conditions under which truthful reporting equilibria will be selected.

conference papers

Akhil Rao, Francesca Letizia (2021): An Integrated Debris Environment Assessment Model, for the 8th European Conference on Space Debris, paper

Abstract: Launch behaviors are a key determinant of the orbital environment. Physical and economic forces such as fragmentations and changing launch costs, or policies like post-mission disposal (PMD) compliance requirements, will alter the relative attractiveness of different orbits and lead operators to adjust their launch behaviors. However, integrating models of adaptive launch behavior with models of the debris environment remains an open challenge. We present a statistical framework for integrating theoretically-grounded models of launch behavior with evolutionary models of the low-Earth orbit (LEO) environment. We implement this framework using data on satellite launches, the orbital environment, launch vehicle prices, sectoral revenues, and government budgets over 2007-2020. The data are combined with a multi-shell and multi-species Particle-in-a-Box (PIB) model of the debris environment and a two-stage budgeting model of commercial, civil government, and defense decisions to allocate new launches across orbital shells. We demonstrate the framework's capabilities in three counterfactual scenarios: unexpected fragmentation events in highly-used regions, a sharp decrease in the cost of accessing lower parts of LEO, and increasing compliance with 25-year PMD guidelines. Substitution across orbits based on their evolving characteristics and the behavior of other operators induces notable changes in the debris environment relative to models without behavioral channels.

Trevor Bennett, Charles Cain, N.S. Campbell, Andrew Gemer, John Marino, Tobias Niederwieser, Akhil Rao (2018) The CENKI Space Economic Simulator: Analytical Verification of an Agent-Based Modeling Engine 2018 IEEE Aerospace Conference Proceedings doi

Trevor Bennett, Charles Cain, N.S. Campbell, Andrew Gemer, John Marino, Tobias Niederwieser, Akhil Rao (2018) The CENKI Space Economic Simulator: Demonstrating Agent-Based Modeling on Satellite Market Data 2018 IEEE Aerospace Conference Proceedings doi