Scoring Probability Forecasts by a User’s Bets Against a Market Consensus

2021 ◽  
Author(s):  
David Johnstone ◽  
Stewart Jones ◽  
Oliver Jones ◽  
Steve Tulig

The purpose of our paper is to describe a probability scoring rule that reflects the economic performance of a hypothetical investor who acts upon the probability forecasts emanating from a given model or human expert by trading against a market-clearing consensus of competing models and forecasts. The probability forecasts being compared are aggregated by an equilibrium condition into a market consensus reflecting the wisdom of the crowd. A good forecaster (model or human expert) is measured as one who allows the user to bet profitably against the market consensus. By asking forecasts to beat the market, forecasters are discouraged from herding and motivated to obtain better information than rival forecasters. We illustrate and prove that each trader’s personal incentive to hedge or fudge disappears when the number of forecasts in the market is sufficiently large. Our score exhibits the forecaster’s ability to assist economically profitable action and reveals how the user’s profits depend strongly on the accuracy of the forecasts and the decision rule (boldness) with which they are acted upon.

2020 ◽  
Author(s):  
Mª de la Cruz Déniz‐Déniz ◽  
Mª Katiuska Cabrera-Suárez ◽  
Josefa D. Martín-Santana

1991 ◽  
Vol 30 (03) ◽  
pp. 187-193 ◽  
Author(s):  
H. J. Moens ◽  
J. K. van der Korst

AbstractA Bayesian decision support system was developed for the diagnosis of rheumatic disorders. Knowledge in this system is represented as evidential weights of findings. Simple weights were calculated as the logarithm of likelihood ratios on the basis of 1,000 consecutive patients from a rheumatological clinic. The effect of various methods to improve performance of the system by modification of the weights was studied. Three methods had a mathematical basis; a fourth consisted of weights adapted by a human expert, which allowed inclusion of diagnostic rules such as defined in widely accepted criteria sets. The system’s performance was measured in a test population of 570 different cases from the same clinic and compared with predictions of diagnostic outcome made by rheumatologists. The weights from a human expert gave optimal results (sensitivity 65% and specificity 96%), that were close to the physicians’ predictions (sensitivity 64% and specificity 98%). The methods to measure the performance of the various models used in this study emphasize sensitivity, specificity and the use of receiver operating characteristics.


1997 ◽  
Vol 78 (02) ◽  
pp. 794-798 ◽  
Author(s):  
Bowine C Michel ◽  
Philomeen M M Kuijer ◽  
Joseph McDonnell ◽  
Edwin J R van Beek ◽  
Frans F H Rutten ◽  
...  

Summary Background: In order to improve the use of information contained in the medical history and physical examination in patients with suspected pulmonary embolism and a non-high probability ventilation-perfusion scan, we assessed whether a simple, quantitative decision rule could be derived for the diagnosis or exclusion of pulmonary embolism. Methods: In 140 consecutive symptomatic patients with a non- high probability ventilation-perfusion scan and an interpretable pulmonary angiogram, various clinical and lung scan items were collected prospectively and analyzed by multivariate stepwise logistic regression analysis to identify the most informative combination of items. Results: The prevalence of proven pulmonary embolism in the patient population was 27.1%. A decision rule containing the presence of wheezing, previous deep venous thrombosis, recently developed or worsened cough, body temperature above 37° C and multiple defects on the perfusion scan was constructed. For the rule the area under the Receiver Operating Characteristic curve was larger than that of the prior probability of pulmonary embolism as assessed by the physician at presentation (0.76 versus 0.59; p = 0.0097). At the cut-off point with the maximal positive predictive value 2% of the patients scored positive, at the cut-off point with the maximal negative predictive value pulmonary embolism could be excluded in 16% of the patients. Conclusions: We derived a simple decision rule containing 5 easily interpretable variables for the patient population specified. The optimal use of the rule appears to be in the exclusion of pulmonary embolism. Prospective validation of this rule is indicated to confirm its clinical utility.


2013 ◽  
pp. 4-23 ◽  
Author(s):  
V. Mau

The paper deals with the trends in the world and Russian economies towards development of a new post-crisis system, including technological and structural transformation. Three main scenarios of Russian economic development (conservative, innovation and acceleration) are discussed basing on historical analysis of Russian economic performance since 1970-s when oil boom started. On this basis key challenges of economic policy in 2013 are discussed.


2014 ◽  
pp. 4-32 ◽  
Author(s):  
V. Mau

The paper deals with Russian social and economic development in 2013 and prospects for the next year or two. The author discusses the logic and trends of the global crisis started in 2008. This is the basis for further analysis of current Russian economic performance with special emphasis on the problem of growth rates deceleration. Special attention is paid to economic risks and priorities of economic policy.


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