Efficiency in the NFL betting market: modifying and consolidating research methods

Modifying and consolidating previous research methods to generate more reliable estimates, some fairly weak evidence is found of inefficiency in the NFL betting market resulting from a bias favouring home underdog (against away favourite) teams. In contrast to previous research, no evidence is found that ‘momentum strategies’ generate significant returns in this market.     

What drives intermediation costs? A case of tennis betting market

We demonstrate that there is a considerable variation in bookmaker margins across matches, time and bookmakers. Our results imply that using match, tournament and players’ characteristics explains the variations in margins hence, they can be helpful in managing intermediation cost in a market of state-contingent assets: fixed-odds betting markets. We also provide evidence that bookmakers protect themselves by increasing odds on the favourite player, thus attracting more bettors to the favourite player, while deterring bettors from betting on the underdog by reducing the odds. By that process, bookmakers are possibly sacrificing a portion of their margin.     

Information and efficiency: an empirical study of a fixed odds betting market

The efficiency of the fixed odds betting market for football in England is investigated. It is the efficiency of how market participants utilize available information that is tested. A model of bookmaker behaviour is presented in which the bookmaker maximizes their expected share of the total amount bet. It is found that an expected profit maximizing bookmaker could set market inefficient odds. Several empirical tests using the ordered probit model with data on prices and publicly available information are carried out. Evidence of market inefficiency is identified offering profitable betting opportunities.     

Game over? Assessing the impact of the emergence of a profitable wagering strategy in major league baseball wagering markets

Testing the impact of profitable investment strategies is often hampered by the practical difficulties of determining who knew what, and when. This study examines the impact of the publication of a profitable wagering strategy on the Major League Baseball wagering market. While standard measures of market efficiency characterized the Major League Baseball win–loss moneyline market to be efficient, previous works shows that wagering on underdogs early in the season can generate persistent profits. Though the overall efficiency of the baseball wagering market remained after publication, these profitable opportunities dissipated. Bettor behaviour is found to play varying roles across different wagering strategies; up to half of the drop in returns can be attributed to wagering market participant behaviour.     

Variable factors and eficiency in the US seel idustry: a Production Frontier Analysis

In an efficient NFL beting market, point spreads incorporate all relevant information contained in past game outcomes. Efficiency implies that trading rules based on past game outcomes should not be able to produce a consistent pattern of winners over losers. This study identifies 15 trading rules based on historical game outcomes and, using simulated gambling, tests them over the 1984–1986 NFL seasons. The study's main finding indicates that the NFL betting market is efficient, but does identify a small set of profitable trading rules over this time period.     

The Favourite-Longshot Bias and Market Efficiency in UK Football betting

It is shown that the individual fixed-odds betting market on UK football exhibits the same favourite-longshot bias as that found in horse-racing. The bias appears both in betting on results (home win, away win or draw) and in betting on specific scores, and there are certain trading rules which appear to be profitable. Poisson and Negative Binomial regressions are carried out to estimate the mean number of goals scored by a team in a match with given market odds for the various outcomes. Tables of odds for individual scores are derived and these appear to fit the actual outcomes far better than those of the bookmaker.     

OPTIMAL PRICE SETTING IN FIXED‐ODDS BETTING MARKETS UNDER INFORMATION UNCERTAINTY

This paper develops a model of optimal pricing under information uncertainty for fixed‐odds betting markets. The model suggests that bookmakers require a premium for quoting the odds several days before an event. This premium reflects the uncertainty of public information that can be exploited by expert bettors. The model predicts that when bookmakers set optimal prices, expected returns to bettors increase as a monotonic function of winning probabilities. In this manner, an information‐based explanation is given for the celebrated favourite‐longshot bias in fixed‐odds. Using an extensive data‐set of football odds from two major European bookmakers, we estimate the probability of informed betting.     

Foreign aid and economic growth in Cameroon

A recent study of the fixed-odds betting market on baseball games, while finding that the betting market is generally efficient, also found evidence of an underbetting on underdog teams. This article examines the evidence for this new anomaly. It corrects Woodland and Woodland's estimates of the commission, subjective win probabilities and test statistics. The efficiency null hypothesis cannot be rejected for all of their tests when revised test statistics are calculated for their sample period (however, like them, it was found that slight underdogs are underbet). It is also shown that their bias is not simply a bias involving favourites and underdogs. Whether underdogs are playing at home or away also seems to matter in their sample period. As well a positive relationship between returns and subjective probabilities was found for underdogs and favourites, a relationship suggestive of a favourite-longshot bias rather than its reverse. It is concluded that there is insufficient evidence to claim that this bias is a ‘true market inefficiency’.     

Information Efficiency in Betting Markets: a Survey

The concept of information efficiency is central to many studies of financial markets, and these studies have been well surveyed to date. A betting market is an example of a simple financial market, but one which offers researchers the added advantage that it is characterized by a well-defined termination point at which each asset (or bet) possesses a definite value. In consequence, it is much more convenient to use this particular context to formulate tests of information efficiency, and from these tests to draw useful conclusions. This paper surveys the rapidly growing literature which has to date addressed this issue of information efficiency in betting markets.     

Betting market inefficiencies are short-lived in German professional football

In this article, we argue that potential inefficiencies on betting markets are more likely to exist at the very beginning of a season, when the available information on the teams’ playing strength is difficult to evaluate. This lack of reliable information should be particularly large in the case of recently promoted teams that have typically undergone major changes in the composition of their roster following their promotion. Without any information on the latter teams’ potential performance, they are particularly difficult to evaluate, which may eventually lead to inefficiencies and positive returns on investment in the betting market. We analyse odds from German first division Bundesliga soccer for the seasons from 2002/03 to 2015/16 to find betting market inefficiencies at the start of the season. As expected, betting on recently promoted team wins generates temporarily positive returns, especially for away games. These results suggest bookmakers to underestimate promoted teams’ ability to familiarize with the conditions in the new league, such as having to play in front of larger, often hostile crowds.     

Investment horizons,cash flow news,and the profitability of momentum and reversal strategies in the Chinese stock market

This study investigates the profitability of momentum and reversal strategies of different investment horizons in the Chinese stock market. The findings indicate that momentum strategies are profitable for investment horizons less than one week. For longer investment horizons, reversal strategies are profitable. This result is very different from the US market, where profitable momentum strategies yield to much longer investment horizons. We show that this is because investors in Chinese stock market generally overreact to the company cash flow news while investors in US market underreact to cash flow news.     

An examination of the empirical derivatives of the favourite-longshot bias in racetrack betting

Market efficiency dictates it equally profitable to bet on any racing participant, including the favourite or longshot. However, a well-documented anomaly is that racetrack bettors tend to overbet longshots and underbet favourites. This study presents and tests two theoretical explanations for this favourite-longshot bias. The unparalleled richness of the data allows the exploration of how the bias changes with several key variables. This study finds the most popular current explanation for the bias, the risk preference model, cannot explain the data as well as an information-based model, in which the bias depends on bet complexity and the information possessed by bettors.     

To bet or not to bet: a reality check for tennis betting market efficiency

We present evidence that the tennis betting market appears to be much more efficient than suggested by previous studies. More specifically, we study the market efficiency by studying the forecasting performance of a diversified set of 40 betting rules in two ways: by searching for the existence of a return differential between betting rules and by analysing the profitability of betting rules. Even though individual tests provide evidence that, within our universe of betting rules, positive returns can be achieved, when data-snooping bias is taken into account, the evidence diminishes. Subsequently, we also find very little evidence of return differentials between betting rules. These results cast doubts on previous research as they suggest that when the potential detrimental effects of data-dreading are taken into account, betting markets in general might not, ultimately, be so inefficient.     

Globally evolutionarily stable portfolio rules

The paper examines a dynamic model of a financial market with endogenous asset prices determined by short-run equilibrium of supply and demand. Assets pay dividends that are partially consumed and partially reinvested. The traders use fixed-mix investment strategies (portfolio rules), distributing their wealth between assets in fixed proportions. Our main goal is to identify globally evolutionarily stable strategies, allowing an investor to “survive,” i.e., to accumulate in the long run a positive share of market wealth, regardless of the initial state of the market. It is shown that there is a unique portfolio rule with this property—an analogue of the famous Kelly rule of “betting your beliefs.” A game theoretic interpretation of this result is given.     

The closed‐loop effect and the profitability of horizontal mergers

Abstract.  We study the profitability of horizontal mergers in a dynamic competition context with sticky prices. It is shown that, when firms use open‐loop strategies, a merger is profitable only if the share of the market that merges is significant enough. In the case where firms use closed‐loop strategies we provide a method to conduct analytically the study of the profitability of horizontal mergers. We first prove the existence of an equilibrium of the game when a subset of firms merges. When firms use feedback strategies, mergers are profitable even when the share of the market that merges is arbitrarily small. JEL Classification:D4, L13     

Why are some favourite-longshot biases positive and others negative?

Most studies of both pari-mutuel and fixed-odds betting markets have shown a systematic tendency for the expected return to bets at lower odds to exceed those at higher odds. Some work, however, has revealed in certain markets the absence or even reversal of this bias. We present a model which distinguishes two separate types of bettor, and use this to demonstrate how transactions costs, the extent of public information, and consumption benefits of betting can explain the disparities. Our empirical evidence, taken from a fixed-odds market, lends support to our theoretical conclusions.     

Testing for rational expectations in the UK National Lottery

The concept of rational expectations has typically been assumed, without testing, in the analysis of consumer demand and market efficiency in betting markets, including betting on lottery games. Lottery games offer an excellent opportunity to test how participants process the information that is available to them. Using the UK National Lottery as our particular case, we find that participants, in general, efficiently process available information. Specifically, they act as if they can, on average, forecast the level of sales for a given drawing.     

Searching for the favourite-longshot bias down under: an examination of the New Zealand pari-mutuel betting market

This paper tests for the presence of the favourite-longshot bias in a new setting. This bias #150 the tendency for bettors to underbet favourites and overbet longshots #150 has been found in most studies of pari-mutuel and bookmaking betting markets in the USA, the UK and Australia. However, there is growing evidence that in at least some pari-mutuel betting markets there is no favourite-longshot bias. This paper examines the previously unexplored New Zealand pari-mutuel betting market on horse races for evidence of this bias. Utilizing a large sample of recent New Zealand thoroughbred horse races, it is found that while early, off-track bettors price this bias into odds, late (on-and off-track) bettors eliminate much of the bias by the close of betting. That is, the results reinforce the view that not all pari-mutuel betting markets are characterized by a favourite-longshot bias at the close of betting. Evidence is also found that late bettors in this market are smart bettors.     

Preseason bias in the NFL and NBA betting markets

This study extends research in the sports gaming literature by examining the efficiency of betting markets related to preseason professional sporting events. Using NFL (1995–2014) and NBA (2005–2014) data from preseason games, we examine the pricing efficiency of point spreads in these markets and consider evidence of systematic mispricing. Findings suggest point spreads are too large in these situations, providing a profitable betting opportunity for those willing to systematically wager on underdogs. Similar findings are not seen within the context of NFL or NBA regular seasons. These findings are more pronounced as preseason point spreads become larger. Further stratification by week of the NFL preseason demonstrates that underdogs discontinue their superior performance for the one week (Week 3) in which clubs tend to expel a higher level of effort.     

The Relationship Between Economic Factors and Equity Markets in Central Europe

This paper investigates the possibility that newly-emerging equity markets in Central Europe exhibit semi-strong form efficiency such that no relationship exists between lagged values of changes in economic variables and changes in equity prices. We find that while there are connections between the real economy and equity market returns in Poland and Hungary, these links occur with lags, suggesting the possibility of profitable trading strategies based on public information and rejecting semi-strong efficiency. For the Czech Republic the situation is more complex. In recent periods, little connection exists between lagged economic variables and equity market returns. Although this finding might be viewed as consistent with semi-strong efficiency, in fact there is also little connection between current economic values and stock prices in the Czech Republic. Thus, instead of processing information efficiently, the Czech market appears to be entirely divorced from the real world. It is suggested that the difference in the current status of these markets may be due to the different methods by which they were created.