Prediction Markets to Forecast Electricity Demand

A preference is invariant with respect to a transformation tau if its ranking of acts is unaffected by a reshuffling of the states under tau. We show that any invariant preference must be parametric: there is a unique sufficient set of parameters such that the preference ranks acts according to their expected utility given the parameters. This property holds for all non-trivial preferences, provided only that they are reflexive, transitive, monotone, continuous and mixture linear.

Finitely additive representation of Lp spaces

AbstractLet λ¯ be any atomless and countably additive probability measure on the product space {0,1}N with the usual σ-algebra. Then there is a purely finitely additive probability measure λ on the power set of a countable subset T⊂T¯ such that Lp(λ¯) can be isometrically isomorphically embedded as a closed subspace of Lp(λ). The embedding is strict. It is also ‘canonical,’ in the sense that it maps simple and continuous functions on T¯ to their restrictions to T

Undescribable Events

We develop a model of undescribable events. Examples of events that are well understood by economic agents but are prohibitively difficult to describe in advance abound in real-life. This notion has also pervaded a substantial amount of economic literature. We put forth a model of such events using a simple co-insurance problem as backdrop. Undescribable events in our model are understood by economic agents - their consequences and probabilities are known - but are such that every finite description of such events necessarily leaves out relevant features that have a non-negligible impact on the parties’ expected utilities. We also show that two key ingredients of our model - probabilities that are finitely additive but fail countable additivity, and a state space that is small (discrete in our model) in a measure-theoretic sense -are necessary ingredients of any model of undescribable events that delivers our results.undescribable events, incomplete contracts, finite invariance, fine variability

A Reputational Model of Authority

: The paper provides a model where authority relationships are founded on reputation. The viability of authority is the result of subordinates' free-riding on each other challenges, reducing the frequency of challenges, and making reputations worth defending. The party with authority secures subordinates' compliance through the payment of rents to influence the extent of their failure to act collectively and exacerbate the free-rider problem they face. The model provides a framework to explain how the magnitude and form of these rents depend on the primitives of the environment and on the authority's design of its reputation. Applications to efficiency wages, dictatorships, and the notion of legitimacy are considered.

A Bayesian Model of Knightian Uncertainty

Abstract: A long tradition suggests a fundamental distinction between situations of risk, where true objective probabilities are known, and unmeasurable uncertainties where no such probabilities are given. This distinction can be captured in a Bayesian model where uncertainty is represented by the agent's subjective belief over the parameter governing future income streams. Whether uncertainty reduces to ordinary risk depends on the agent's ability to smooth consumption. Uncertainty can have a major behavioral and economic impact, including precautionary behavior that may appear overly conservative to an outside observer. We argue that one of the main characteristics of uncertain beliefs is that they are not empirical, in the sense that they cannot be objectively tested to determine whether they are right or wrong. This can confound empirical methods that assume rational expectations.

Aggregate Risk and the Pareto Principle

In the evaluation of public policies, a crucial distinction is between plans that involve purely idiosyncratic risk and those that generate correlated, or aggregate, risk. While natural, this distinction is not captured by standard utilitarian aggregators. In this paper we revisit Harsanyi's (1955) celebrated theory of preferences aggregation and develop a parsimonious generalization of utilitarianism. The theory we propose captures sensitivity to aggregate risk in large populations and can be characterized by two simple axioms of preferences aggregation

Large Non-Anonymous Repeated Games

Saborian [8], following Green [4], studies a class of repeated games where a player's payoff depends on his stage action and an anonymous aggregate outcome, and shows that long-run players behave myopically in any equilibrium of such games. In this paper we extend Sabourian's results to games where the aggregate outcome is not necessarily an anonymous function of players' actions, and where players strategies may depend non-anonymously on signals of other players' behavior. Our argument also provides a conceptually simpler proof of Green and Sabourian's analysis, showing how their basic result is driven by bounds on how many pivotal players there can be in a game.

Pivotal Players and the Characterization of Influence

A player inuences a collective outcome if his actions can change the probability of that outcome. He is �-pivotal if this change exceeds some threshold �. We study inuence in general environments with N players and arbitrary sets of signals. It is shown that inuence is maximized when players' signals are identically distributed and the outcome is determined according to simple majority rule.This leads to the surprising conclusion that majority rules already contain the maximal number of pivotal players. From this we derive a tight bound on average inuence, as well as a tight bound on the number of �-pivotal players, which is independent of N. This analysis is relevant to problems where players' inuence is a key consideration in determining their strategic behavior. The applications we consider include the problem of designing a mechanism for the provision of public goods in the spirit of Mailath and Postlewaite (1990), partnership games, games with production complementarities, and cooperation in a noisy prisoner's dilemma.

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised