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Worst-Case Economics

Worst-Case Economics

Frank Ackerman

(2017)

Abstract

Worst-case scenarios are all too real, and all too common. The financial crisis of 2008 was not the first or the last to destroy jobs, homeownership and the savings of millions of people. Hurricanes clobber communities from New York to Bangladesh. How bad will the next catastrophe be, and how soon will it happen?

Climate and financial crises are serious events, requiring vigorous responses. Yet public policy is trapped in an obsolete framework, with a simplistic focus on average or likely outcomes rather than dangerous extremes. What would it take to create better analyses of extreme events in climate and finance, and an appropriate policy framework for worst-case risks? ‘Worst-Case Economics: Extreme Events in Climate and Finance’ offers accessible and surprising answers to these crucial questions.


“Old-fashioned economics has led to dangerously wrong-headed approaches to climate change and other ‘extreme event’ situations, such as financial crises. In this highly accessible but profound book, Ackerman persuasively shows the urgency of smarter, more recent thinking about how natural and economic systems work and why we need to pay much more attention to worst cases. This is a must-read book for anyone who wants to understand the world we now inhabit.”
—Juliet Schor, author of Plenitude: The New Economics of True Wealth


“Ackerman’s Worst-Case Economics will convince you that the conventional economic modeling of risk is inadequate when financial crashes, environmental collapse and other cataclysmic outcomes are possible and that policies based on prudence regarding the worst-case scenario are needed. An important book and a delight to read.”
—Samuel Bowles, Research Professor and Director, Behavioral Science Program, Santa Fe Institute, New Mexico, USA


Why do climate and financial crises pose such extreme risks? And what does it take to respond effectively to those risks? Extreme weather events – storms and sea-level rise, heat waves, droughts and floods – seem ever more common and extreme, while scientists warn of even greater climate risks ahead. Financial failures on the scale of 2008 make a mockery of the supposed efficiency of the market economy. None of this would be possible in the world as imagined by conventional economics – an imaginary land of gradualism, equilibrium, well-informed rationality and the win-win solutions dealt by the invisible hand.

The erratic rhythm of boom and bust in financial markets could be explained either by the patterns of crowd-following behaviour among investors, or by the unequal distribution of wealth (and the impact of the largest investors on the markets). Climate crises reflect the fact that natural systems can reach tipping points or critical transitions, where gradual change gives way to large-scale discontinuous changes. The economics of climate change has lagged behind the science, understating the severity of the problem and the likelihood of a crash.

While the causes of climate and financial extremes are distinct, the implications for public policy have much in common. The frequency of extreme events, of varying sizes, means that there is no way to predict the likely size of future crises. The traditional approach to risk aversion cannot account for longstanding patterns in financial markets. Better theories of risk call for more precautionary approaches to both financial and climate policy. In the frequent cases in which potential outcomes have unknown probabilities, the best policy is based on the worst-case credible scenario. When a single catastrophic risk commands everyone’s attention, a World War II-style, costs-be-damned mobilization is the right response. There is no formula for perfect responses to extreme risks, but there are important guideposts that point toward better answers.


Frank Ackerman is an economist whose extensive research and writing focus on climate change and energy, environmental policy and cost-benefit analysis.

Table of Contents

Section Title Page Action Price
Cover Cover 1
Front Matter iii
Half-title i
Title page iii
Copyright information iv
Dedication v
Epigraph vi
Table of contents vii
List of figures ix
Chapter 1-17 1
Chapter 1 Introduction 1
Costs of Crisis 2
Beyond Whispers and Tweets 3
Once Upon a Textbook 4
Stuff Happens 6
Making Decisions in the Dark 7
What this Book is not 9
Chapter 2 Steam-Engine Economics 11
The Birth of a Notion 12
Mistakes Were Made 14
The Science of Gradualism 16
An Eighty-Year Odyssey 18
Brownian Motion in the Stock Market 19
Chapter 3 Beyond Homo Economicus 21
Shameless Appearances 23
Losing Gambles 25
The Law of Small Numbers 27
Rational Fools 28
Chapter 4 Big and Dirty 31
Technology and Information 32
Marketing and Market Structure 33
Pricing the Earth 34
Ecological Limits and Learning Curves 35
Chapter 5 Pictures of Improbability 39
Dice Games and the Normal Distribution 39
Normal Distributions in the Real World 42
Abnormal Markets 44
A Variable Amount of Variation 47
Chapter 6 Trillions, or only Hundreds? 51
Picturing the Power Law 53
The Devil May not be in the Details 56
Fat Tails and Bad Weather 57
Too Hot to be Normal 60
Chapter 7 Zipf’s Law and Other Stories 63
Explaining Power Laws 65
Power Law Skeptics 66
The Science of Extremes 67
Rice Piles and Self-Organization 69
Balancing a Chopstick 70
Chapter 8 Ants and Traders 73
Noise Traders and Insect Behavior 74
Intermittent Markets 77
Moving at the Speed of Gossip 78
Chapter 9 Too Big to Ignore 81
From Inequality to Instability 83
Pareto’s Law: The Shape of Inequality 85
The Rich get Richer 86
The Invisible Fistfight 88
Chapter 10 Climate Tipping Points and Known Unknowns 91
Choosing a Disaster 93
Sherlock Holmes and Bayesian Probability 95
Highway to Hell 97
Climate Sensitivity 99
Chapter 11 Predators and Prey 103
Macroeconomics and the Minsky Moment 103
A Cycle or a Crash? 105
Beyond Optimism 107
The Longest-Lived Predator 109
Chapter 12 Good Enough for Government Work 111
Full Employment, Now and Forever 112
Cost-Benefit Analysis Comes to Washington 114
Benefits and Biases 116
In Praise of Inefficiency 117
Chapter 13 Fat Tails and the Failure of Forecasting 121
Calculation or Guesstimates? 122
Monetizing Warming 123
The “Dismal Theorem” 127
Chapter 14 Misunderstanding Risk 131
Insurance and its Limits 132
The Wrong Explanation of Risk 133
The Equity Premium Puzzle 134
Market Myopia 136
Is There a Climate Premium Puzzle? 137
Chapter 15 Choices Beyond Calculation 141
The Price of Precaution 143
The Economics of Ignorance 144
Thresholds for Precaution 145
Decaffeinated Cost-Benefit Analysis 147
Scenario Analysis 149
Chapter 16 Who won World War II? 153
Losing the Peace 156
Postwar Planning 157
Crisis Management as a Way of Life 158
Sacred Values 160
Tweets Versus Reality 162
Chapter 17 Conclusion 165
A Model of Instability 166
Making Policy for Extreme Events 167
Decision Making Without Algorithms 170
End Matter 173