Theoretical analysis and model design of search for ecological conservation redlines based on the sensitivity assessment of ecosystem services

Most small-scale social economies are characterised by their deficiency, lack, and/or difficulty in matching natural data. Against this backdrop, this paper builds a relatively uniform theoretical framework and designs a more economical and objective method for demarcating ecological conservation redlines (ECR) based on sensitivity assessment of ecosystem services. The results show that the sensitivity assessment model designed in this study can identify sensitive zones effectively, and that the ECR in Hubei Province are well within the sensitive zones so identified. The delimited areas based on the sensitive assessment of ecosystem services have great similarities (95%) with the actual ECR areas in Hubei Province. The most ecologically important functional zones (EIFZ) can also be identified using the regional ecological sensitivity coefficient. When the threshold of EIFZ is set higher, the probability that it falls within the ecologically sensitive areas is greater and the ECR delimited by the method proposed in this study will be more reliable. Theoretically, the delimitation of ECR can be inserted at any evaluation level with a grid resolution higher than that of the land use data, which can be used as a supplement to the ECR delimitation method in ecology or geography.     

Are betting returns a useful measure of accuracy in (sports) forecasting?

In an economic context, forecasting models are judged in terms not only of accuracy, but also of profitability. The present paper analyses the counterintuitive relationship between accuracy and profitability in probabilistic (sports) forecasts in relation to betting markets. By making use of theoretical considerations, a simulation model, and real-world datasets from three different sports, we demonstrate the possibility of systematically or randomly generating positive betting returns in the absence of a superior model accuracy. The results have methodological implications for sports forecasting and other domains related to betting markets. Betting returns should not be treated as a valid measure of model accuracy, even though they can be regarded as an adequate measure of profitability. Hence, an improved predictive performance might be achieved by carefully considering the roles of both accuracy and profitability when designing models, or, more specifically, when assessing the in-sample fit of data and evaluating out-of-sample forecasting performances.     

The association between two random elements: A complete characterization and odds ratio models

For random elements X and Y (e.g. vectors) a complete characterization of their association is given in terms of an odds ratio function. The main result establishes for any odds ratio function and any pre-specified marginals the unique existence of a corresponding joint distribution (the joint density is obtained as a limit of an iterative procedure of marginal fittings). Restricting only the odds ratio function but not the marginals leads to semi-parmetric association models for which statistical inference is available for samples drawn conditionally on either X or Y. Log-bilinear association models for random vectors X and Y are introduced which generalize standard (regression) models by removing restrictions on the marginals. In particular, the logistic regression model is recognized as a log-bilinear association model. And the joint distribution of X and Y is shown to be multivariate normal if and only if both marginals are normal and the association is log-bilinear.Acknowledgements The author thanks both referees for their helpful comments which improved the first draft of the paper.     

Informational efficiency and behaviour within in-play prediction markets

Studies of financial market informational efficiency have proven burdensome in practice, because it is difficult to pinpoint when news breaks and is known by some or all the participants. We overcome this by designing a framework to detect mispricing, test informational efficiency and evaluate the behavioural biases within high-frequency prediction markets. We demonstrate this using betting exchange data for association football, exploiting the moment when the first goal is scored in a match as major news that breaks cleanly. There are pre-match and in-play mispricing and inefficiency in these markets, explained by reverse favourite-longshot bias (favourite bias). The mispricing tends to increase when the major news is a surprise, such as a goal scored by a longshot team late in a match, with the market underestimating their chances of going on to win These results suggest that, even in prediction markets with large crowds of participants trading state-contingent claims, significant informational inefficiency and behavioural biases can be reflected in prices.     

Do bookmakers possess superior skills to bettors in predicting outcomes?

In this paper we test the hypothesis that bookmakers display superior skills to bettors in predicting the outcome of sporting events by using matched data from traditional bookmaking and person-to-person exchanges. Employing a conditional logistic regression model on horse racing data from the UK we find that, in high liquidity betting markets, betting exchange odds have more predictive value than the corresponding bookmaker odds. To control for potential spillovers between the two markets, we repeat the analysis for cases where prices diverge significantly. Once again, exchange odds yield more valuable information concerning race outcomes than the bookmaker equivalents.     

The role of small bettors in price formation in betting exchanges

ABSTRACT

The presence of small bettors in betting exchanges generates mispricing, which can lead to exploitation by informed traders or result in permanent price deviations. This paper shows that mispricing from this source is also dependent upon variables of established relevance such as tournament round, the level of attention to the event, the volume of the betting, and bet type, further confirming these findings by means of cumulative accuracy profile (CAP) curves. It also offers evidence of the relevant role played by the type of device used to place the bet, whereby higher mispricing is observed in live bets placed via a mobile device, which appears to be associated with impulsive betting. This last finding could have practical implications for the regulation of the use of mobile devices to access gambling platforms.     

Assessing the Italian tax courts system by weighted three-way log-ratio analysis

Deciding on what should be the most suitable reforms of a national judicial system, whether this means reorganising a courts' structure or offering incetives to judges, requires more empirical evidence. The efficiency of the public judicial system is important to any functioning democracy as it affects several aspects of citizens’ life. As a consequence, new statistical methodologies are required for further valuable insights into the issues that affect the effectiveness of a judicial system.The current study attempts to fill this gap by introducing a new statistical method to investigate the heterogeneity among Italian judicial courts. Here we propose a generalisation of log-ratio analysis for the analysis of the association between the variables of a three-way contingency table. Our focus of this investigation will be on the tax court system of the Italian judicial system.Log-ratio analysis presents many advantages, two of which are the computation and the visual representation of the odds ratios on which the analysis is based. For three-way tables, a conditional odds ratio reflects the likelihood that an event (say tax disputes) will take place in a particular geographical area (say North Italy) instead of an another (say South Italy) given a specific condition (type of justice court).Interestingly, the three-way log-ratio analysis presented in this paper allows one to visually describe these conditional odds-ratios in terms of point distances in a biplot between the types of justice court located in different geographical areas of Italy.     

Subtle price discrimination and surplus extraction under uncertainty

This paper provides a solution to Proebsting’s Paradox, an argument that appears to show that the investment rule known as the Kelly criterion can lead a decision maker to invest a higher fraction of his wealth the more unfavorable the odds he faces are and, as a consequence, risk an arbitrarily high proportion of his wealth on the outcome of a single event. The paper shows that a large class of investment criteria, including ‘fractional Kelly’, also suffer from the same shortcoming and adapts ideas from the literature on price discrimination and surplus extraction to explain why this is so. The paper also presents a new criterion, dubbed the doubly conservative criterion, that is immune to the problem identified above. Immunity stems from the investor’s attitudes toward capital preservation and from him becoming rapidly pessimistic about his chances of winning the better odds he is offered.     

Revisiting games of incomplete information with analogy-based expectations

This paper studies the effects of analogy-based expectations in static two-player games of incomplete information. Players are assumed to be boundedly rational in the way they forecast their opponent's state-contingent strategy: they bundle states into analogy classes and play best-responses to their opponent's average strategy in those analogy classes. We provide general properties of analogy-based expectation equilibria and apply the model to a variety of well known games. We characterize conditions on the analogy partitions for successful coordination in coordination games under incomplete information [Rubinstein, A., 1989. The electronic mail game: Strategic behavior under ‘almost common knowledge’. Amer. Econ. Rev. 79, 385–391], we show how analogy grouping of the receiver may facilitate information transmission in Crawford and Sobel's cheap talk games [Crawford, V.P., Sobel, J., 1982. Strategic information transmission. Econometrica 50, 1431–1451], and we show how analogy grouping may give rise to betting in zero-sum betting games such as those studied to illustrate the no trade theorem.     

Learning, price formation and the early season bias in the NBA

We test the NBA betting market for efficiency and find that totals lines are significantly biased early each season, yet sides lines do not show a similar bias. While market participants generally force line movements in the correct direction from open to close, they do not fully remove the identified bias in totals lines. This inefficiency enables a profitable technical trading strategy, as the resulting win rate of our proposed simple betting strategy against the closing totals line is 56.72%.