Exploiting sports-betting market using machine learning

We introduce a forecasting system designed to profit from sports-betting market using machine learning. We contribute three main novel ingredients. First, previous attempts to learn models for match-outcome prediction maximized the model’s predictive accuracy as the single criterion. Unlike these approaches, we also reduce the model’s correlation with the bookmaker’s predictions available through the published odds. We show that such an optimized model allows for better profit generation, and the approach is thus a way to ‘exploit’ the bookmaker. The second novelty is in the application of convolutional neural networks for match outcome prediction. The convolution layer enables to leverage a vast number of player-related statistics on its input. Thirdly, we adopt elements of the modern portfolio theory to design a strategy for bet distribution according to the odds and model predictions, trading off profit expectation and variance optimally. These three ingredients combine towards a betting method yielding positive cumulative profits in experiments with NBA data from seasons 2007–2014 systematically, as opposed to alternative methods tested.     

Estimating the probability of a match using microeconomic data for the youth labour market

In this paper, we estimate the probability of a match for contacts between job seekers and vacancies. We relate the determinants of a match to the characteristics of the job seeker, the vacancy, and labour market conditions. Our main results are: ethnic minorities are discriminated against, but women are not; employers ‘cream’ the market and job seekers are ranked by their labour market state; high wage offers have a lower probability of a match; the probability of filling a job vacancy falls with vacancy duration, the higher stock of unemployed youths in a labour market, and the larger Careers Service; the probability of a match increases with job seeker duration.     

The Sorting of Female Careers after First Birth: A Competing Risks Analysis of Maternity Leave Duration

A number of contributions have found evidence that motherhood is a critical life event for women's employment careers. This study presents a detailed analysis for the duration of maternity leave in which young mothers can make a transition into different types of employment, unemployment as well as the next birth. We provide a comprehensive picture of the sorting mechanisms that lead to the differentiation of women's employment careers after birth. Our empirical evidence is derived from large‐linked administrative individual labour market data from Germany for a period of three decades. We obtain unprecedented insights into how women's skills, the quality of the previous job match, firm level characteristics, labour market conditions and leave legislation are related to the length of maternity duration. Expansionary leave policies, e.g. are found to be a key factor for the rising share of women who have their second child out of inactivity.     

Match‐Fixing in a Monopoly Betting Market

A monopolist bookmaker may set betting odds on a fairly even contest to induce match‐fixing by an influential corrupt punter. His loss to the corrupt punter is more than made up for by enticing enough ordinary punters to bet on the losing team. This result is in sharp contrast to competitive bookmaking, where even contests have been shown to be immune to fixing. The analysis also reveals a surprising result that the incidence of match‐fixing can dramatically fall when match‐fixing opportunities rise. This is shown by comparing two scenarios—when only one team is corruptible and when both are corruptible. For both teams corruptible, the bookmaker is uncertain about to which team the influential punter will have access, so carefully maneuvering the odds to induce match‐fixing is too costly.     

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.     

Can platform competition support market segmentation? Network externalities versus matching efficiency in equity crowdfunding markets

We investigate whether, in spite of the existence of cross‐market network externalities, platform competition can lead to segmentation of the two sides of the market served by the platforms. We address this question in the context of competition between two equity crowdfunding platforms that connect startups looking for capital with prospective investors. Given the heterogeneity in the populations of startups and investors in terms of the riskiness of the former population and the degree of risk aversion of the latter population, we investigate whether there exists an equilibrium where the two populations are segmented to ensure an improved match between them. We find that the segmenting equilibrium can arise only when compatibility in terms of their risk profiles is of high importance to both populations, and compatibility is significantly more important than the size of the network externality considered by startups. Segmentation is likely to improve the welfare of both populations when the basic benefit from any kind of match is relatively high.     

Is there a risk–return trade‐off? Evidence from high‐frequency data

This paper examines the intertemporal relation between risk and return for the aggregate stock market using high‐frequency data. We use daily realized, GARCH, implied, and range‐based volatility estimators to determine the existence and significance of a risk–return trade‐off for several stock market indices. We find a positive and statistically significant relation between the conditional mean and conditional volatility of market returns at the daily level. This result is robust to alternative specifications of the volatility process, across different measures of market return and sample periods, and after controlling for macro‐economic variables associated with business cycle fluctuations. We also analyze the risk–return relationship over time using rolling regressions, and find that the strong positive relation persists throughout our sample period. The market risk measures adopted in the paper add power to the analysis by incorporating valuable information, either by taking advantage of high‐frequency intraday data (in the case of realized, GARCH, and range volatility) or by utilizing the market's expectation of future volatility (in the case of implied volatility index). Copyright © 2006 John Wiley & Sons, Ltd.     

Matching markets and cultural selection

Review of Economic Design - We study the implications of two different matching mechanisms: bargaining in match (BIM) and binding agreement in the matching market (BAMM) in the context of cultural...     

Odds-setting efficiency in gambling markets: Evidence from the PGA TOUR

This paper describes the gambling market for PGA TOUR events for the 2002 season. The extent to which the odds predict the outcome is examined, illustrating how much information is captured in the odds and whether there are any identifiable biases in the odds. The overall implied profit to the casino is calculated as well as the returns to several naive betting strategies. By splitting the sample based on whether or not Tiger Woods is in the tournament, a “Tiger Woods effect” or a “thin market versus thick market effect” can be examined. On the whole, efficient markets propositions hold up, but the overwhelming share of the variation in the tournament outcome remains unexplained.     

On determining probability forecasts from betting odds

We show that the probabilities determined from betting odds using Shin’s model are more accurate forecasts than those determined using basic normalization or regression models. We also provide empirical evidence that some bookmakers are significantly different sources of probabilities in terms of forecasting accuracy, and that betting exchange odds are not always the best source, especially in smaller markets. The advantage of using Shin probabilities and the differences between bookmakers decrease with an increasing market size.     

Do demand curves for stocks slope down?: Evidence from aggregate data

We examine whether the aggregate demand curve for stocks is downward sloping. As a proxy for aggregate demand, we use net outflows (dividends plus repurchases less net issues) from the stock market scaled by the previous year's market capitalization. To disentangle the information and price pressure effects from the demand curve effects, we use an information-free demographic variable as an instrument and look at the relation between annual changes in aggregate demand and excess market return. We find that information-free changes in the annual aggregate demand for stocks do not lead to changes in the annual excess market return. This finding supports long-term horizontal demand curves for stocks.     

Value relevance and the dot-com bubble of the 1990s

During the dot-com bubble of the 1990s, equity market valuation was a popular topic for investors, financial analysts and academics. Some questioned whether traditional accounting and financial information had lost its value relevance, as stocks traded at multiples of earnings well in excess of historic levels, leading Alan Greenspan to caution against “irrational exuberance.” This study examines the relation between market valuation and traditional accounting/financial information before, during and after the bubble. We confirm previous research that documents a decline in the relation between market value and traditional accounting information leading up to the bubble period. However, we also document that after the collapse of the bubble in 2000 this trend reverses. We also examine two related metrics that may provide a rational explanation for this phenomenon, including the quality of earnings, and the aggressiveness of financial analysts’ forecasts, finding some support that earnings quality may contribute to the changes in value relevance, but not the aggressiveness of analyst forecasts.     

The Influence of Managerial Ownership on Bank Market Value,Performance, and Risk: Evidence from Banks Listed on the Stoxx Global Index

We follow agency theory to assess the influence of managerial ownership on the market value, performance, and risk of 123 listed banks in 23 countries included in the STOXX Global Index in 2007 and 2010. After controlling for bank characteristics, regulatory restrictions, and macroeconomic conditions, our findings show a positive relation between managerial ownership and both market value (Tobin's Q) and performance (ROA and ROE). Moreover, we find a negative relation between managerial ownership and risk (EDF, NPL/L, and Z‐SCORE). Bank market value and performance is a non‐linear, inverse U‐shaped function of managerial ownership. The negative relation between managerial ownership and bank risk is also non‐linear and U‐shaped. Our results remain robust to reverse causality. In their effort to immunize the global financial system from systemic risks, central banks and practitioners should find our results relevant for regulation purposes.     

Price-matching policies: An empirical case

Promises by retailers to match the prices of their competitors give an impression of fierce price competition. These policies, however, may deter rivals from cutting prices because the threat of price matching makes it more likely that market share will not be gained. This paper empirically tests these two conflicting theories using data collected from grocery stores in a market where several stores had announced that they would match the prices of the low-price supermarket. The evidence supports the theory that price-matching policies help supermarkets avoid price competition and therefore lead to generally higher prices.     

Job search incentives and job match quality

We examine the impacts of time-limited unemployment insurance (UI) and active labor market programs (ALMP) on the duration and outcome of job search in Norway. We use a comprehensive simultaneous equations model accounting for i) the duration of unemployment spells; ii) their outcomes, iii) subsequent employment stability; and iv) the earnings level associated with the first job. We find that time invested in job search pays off in form of higher earnings once a job match is formed. ALMP raises the probability of eventually finding a job as well as expected earnings, but at the cost of lengthening job search.     

Investments and the holdup problem in a matching market

This paper studies the properties of the steady state equilibrium in a bilateral matching market with ex ante investments at the market entry stage. Investment incentives depend on search frictions because both parties in a match are partially locked-in when they bargain over the joint surplus from their sunk investments. The associated holdup problem is more important for the long side of the market. In the extreme case of perfectly substitutable investments only the agents on the short side make investments. When market frictions become negligible, the market equilibrium approaches the Walrasian outcome.     

The influence of ETFs on the price discovery of gold, silver and oil

In this study we examine gold, silver and oil exchange traded funds (ETFs) and their relation to their respective futures instruments and underlying commodities by using intradaily data. We find that the gold, silver and oil ETFs closely track the performance of their underlying assets by using tracking error and pricing deviation metrics. It has been documented in the finance literature that price discovery occurs in the futures market. We test whether in recent times the existence of ETFs has changed the dominating role of the futures market in price discovery. We find that the availability of ETFs has shifted price discovery for gold and silver to the ETF market, while the oil market has price discovery occurring still predominantly in the futures market.     

Common ownership,institutional investors,and welfare

This study evaluates the effects of institutional investors' common ownership of firms competing in the same market. Overall, common ownership has two opposing effects: (a) it serves as a device for weakening market competition, and (b) it induces diversification, thereby reducing portfolio risk. We conduct a detailed welfare analysis within which the competition‐softening effects of an increased degree of common ownership is weighted against the associated diversification benefits.     

Product Differentiation and Upstream-Downstream Relations

This paper examines the relationship between a differentiated downstream market and a specialized upstream market. We analyze three different types of vertical relation between the upstream and downstream sectors when the upstream market supplies specialized and complementary inputs to a downstream product-differentiated market. The first is the benchmark case of decentralized markets, the second is a network of alliances among upstream suppliers, and the third is partial vertical integration. We identify the perfect equilibrium for a symmetric model in each case and show that there is no simple relationship between the degree of connection between upstream and downstream firms and profitability. The key factor affecting prices and the relative profitability of the different market organizations is the degree of product differentiation among the downstream firms, because it affects the intensity of competition among upstream suppliers. We show that vertical foreclosure is not an equilibrium strategy.