Showing papers in "International Gambling Studies in 2011"
TL;DR: The British Gambling Prevalence Survey (BGPS2010) as mentioned in this paper examined how people gamble and ways in which online and offline gambling are integrated, and found that the majority of online gamblers were also offline gamblers, and a broader taxonomy of gambling subgroups was evident.
Abstract: This paper presents data from the British Gambling Prevalence Survey (BGPS) 2010, a large-scale random probability survey of adults (n = 7756), to examine how people gamble and ways in which online and offline gambling are integrated. Fourteen per cent of respondents were past year Internet gamblers (7% if purchase of lottery tickets online is excluded). The majority of online gamblers were also offline gamblers and a broader taxonomy of gambling subgroups was evident. This included those who chose different mediums of access for different activities and those who gambled online and offline on the same activity (mixed mode gamblers). These mixed mode gamblers had the highest rates of gambling involvement and higher problem gambling prevalence rates. Direct comparisons between Internet and non-Internet gamblers therefore ignore key questions of how people integrate online provisions with offline activities which may have important implications for our understanding of the relative risks associated with online gambling.
177 citations
TL;DR: In this paper, a comparative evolution of online gambling in Australia and Canada is examined, and the respective social, legal, economic, and political responses are compared, highlighting the unique paths possible, yet the similarities between these jurisdictions pro...
Abstract: Following the rapid progression of Internet gambling, governments internationally are struggling to create and enact appropriate and effective regulations. A situation of inter-jurisdictional inconsistency exists and regulatory frameworks are constantly changing, with international policies of prohibition, legalization or partial legalization, or imprecise legal limbo. The ambiguity of the current situation and questionable effectiveness of policies in place makes it difficult for gambling operators, treatment providers, players and other stakeholders to formulate appropriate responses to online gambling. This article aims to bring some clarity and offer guidance for the effective implementation of gambling policy by examining the comparative evolution of Internet gambling in Australia and Canada, and the respective social, legal, economic and political responses. The differences in the development of online gambling highlight the unique paths possible, yet the similarities between these jurisdictions pro...
104 citations
TL;DR: In this paper, behavioural markers for high-risk Internet gambling using a new casino data set of active real money Internet gamblers are identified and a framework for using behavioural analysis to educate players about risks associated with gambling is proposed.
Abstract: The Internet gambling industry has witnessed tremendous growth in recent years. Nonetheless, our understanding of Internet problem gambling behaviour remains in its infancy. In this paper we build on previous research analysing behavioural markers for high-risk Internet gambling using a new casino data set of active real money Internet gamblers. We assess the first month of play following registration using four behavioural markers: trajectory, frequency, intensity and variability. Our findings identify groups of gamblers who show signs of potentially risky behaviours, specifically gambling intensity and frequency. These gamblers also spend time gambling on slots Internet games. These findings provide a basis for using behavioural analysis to educate players about risks associated with gambling. We suggest a framework for how this can be implemented. Further research leading to the identification of risk factors for problem gambling using new methodologies and data sets will increase the clinical understa...
83 citations
TL;DR: In this paper, the authors identify communication-based indicators for gambling-related problems in the setting of online gambling and use a log-linear model to predict 76.6% of the cases.
Abstract: Early detection is an effective building block for the prevention of problem gambling. This study aims to identify communication-based indicators for gambling-related problems in the setting of online gambling. In the framework of a semi-structured interview, customer service employees of three online gambling operators were surveyed, to identify indicators in customer correspondence could be used as a predictor for gambling-related problems. In a confirmatory part of the study, we investigated to what degree these indicators are able to predict problem gambling in a prospective empirical design. An optimally parsimonious log-linear model, was able to correctly predict 76.6% of the cases. Discussed in the light of this evidence, communication-based indicators could constitute an effective component of early detection. Due to the fact that the internet offers optimal conditions for consistent monitoring and objective analysis, the suggested predictive model could be combined with other models, relying on t...
74 citations
TL;DR: In this article, the psychophysiological responses of 65 participants to wins, losses and near-misses while playing a slot machine simulator were found to be subjectively arousing outcomes that promote further slot machine play.
Abstract: Near-misses in slot machines resemble jackpot wins but fall just short (e.g. two red sevens on the payline and a third just above). These outcomes have been shown to be subjectively arousing outcomes that promote further slot machine play. We assessed the psychophysical responses of 65 participants to wins, losses and near-misses while playing a slot machine simulator. Skin conductance responses were significantly larger for near-misses than either wins or losses. Similarly, heart rate deceleration was significantly larger for near-misses than either wins or losses. These arousal responses were not mediated by players' problem gambling status – near-misses generated large arousal responses even among novice players. We propose that these arousal patterns are due to the frustration of just missing a big win. This research shows the psychophysiological responses triggered by near-misses, and furthers our understanding of how near-misses promote further play.
68 citations
TL;DR: In this paper, the authors conducted a review of the literature to outline the advantages and current status of self-guided online interventions for gambling-related problem and concluded that online self-help programs should be offered as an alternative means to access treatment for gamblers reluctant to pursue traditional options.
Abstract: A minority of problem gamblers access formal treatment. Factors contributing to this low service utilization rate include geographical and time constraints, a desire to selfmanage problems, shame, denial and concerns over privacy/confidentiality. The Internet is an effective medium for the delivery of health-related information, selfassessment, counselling, peer-based support and other therapeutic interventions. Consequently, online self-help programs should be offered as an alternative means to access treatment for gamblers reluctant to pursue traditional options. Benefits of the Internet include its capacity to provide a systematic delivery of cognitive-behavioural therapies, practical visual demonstrations of probabilities correcting erroneous beliefs, accessibility, convenience, cost-effectiveness, anonymity and privacy. We conducted a review of the literature to outline the advantages and current status of self-guided online interventions for gambling-related problem. Although this is a new field, empirical evidence indicates that online self-guided interventions are efficacious and represent an important treatment adjunct for individuals with gambling-related problems.
67 citations
TL;DR: The emergence of player account-based gambling is a result of escalating technological sophistication and the incorporation of these developments into gambling as discussed by the authors, which refers to gambling from a centralized account that is linked to an identified individual.
Abstract: The emergence of player account-based gambling is a result of escalating technological sophistication and the incorporation of these developments into gambling. This term refers to gambling from a centralized account that is linked to an identified individual. Player account-based gambling is increasingly being utilized for multiple forms of Internet, mobile and land-based gambling through player cards and user-names. Player accounts track and store a wealth of data on gambling behaviour and related activities. Gambling research has been justifiably criticized for its reliance on self-report rather than behavioural measures. Research analysing player account data may advance conceptual models, identify behavioural risk factors for problem gambling and evaluate and guide effective policy and responsible gambling programmes. Although research utilizing player account data has unique limitations, it offers considerable benefits for researchers, operators and regulators. Research methodology incorporating the...
63 citations
TL;DR: Based on different characteristics of gambling types, the authors developed an assessment tool to evaluate the risk potential of available and planned gambling types in German-speaking countries, and a psychometric validation indicated that the assessment tool was reliable.
Abstract: Based on different characteristics of gambling types, this study aimed to develop an assessment tool to evaluate the risk potential of available and planned gambling types in German-speaking countries. In the first module, 26 experts were interviewed over the course of a Delphi study, and an analysis of those results led to the selection of relevant characteristics and scaling values. Building on the first module, the second module consisted of standardized data collection of nonproblem, problem and pathological gamblers (characteristics: n = 363; scales: n = 356), which served as an empirical validation. Ten characteristics were identified with different weights and differentiated scaling values to evaluate the risk potential, and a psychometric validation indicated that the assessment tool was reliable (α = 0.91; r ik = 0.50; r it = 0.33–0.80). The correlation measures from data of epidemiological studies (R 2 = 0.84) and a treatment survey (p < 0.001) demonstrated that the assessment tool was valid. ...
54 citations
TL;DR: In this article, the authors conducted a randomised controlled trial pilot study with two treatment groups: manualised cognitive behavioural therapy (CBT) and escitalopram combined with CBT.
Abstract: We conducted a randomised controlled trial pilot study (N = 30) with two treatment groups: (1) Manualised cognitive behavioural therapy (CBT) (n = 15) and (2) escitalopram combined with CBT (n = 15) Treatment was administered individually and the CBT included weekly sessions for eight consecutive weeks The treatment with escitalopram lasted for a minimum of 16 weeks (20 mg/day), with an optional continuation for a 6-month follow-up period Repeated measures ANOVA with modified intent-to-treat analyses were conducted Results showed significant time effects on all measures for both treatment conditions, although no significant group or time × group effects The results indicated that both treatments were effective in the short term (effect sizes (ES) ranging from 045 to 091 for the CBT group and 027 to 072 for the escitalopram+CBT group), and that adding CBT to escitalopram had no additional statistically significant effect (between-group ES of 011 and 029 for primary outcome measures at 16-weeks
52 citations
TL;DR: Orford as discussed by the authors argued that we do have choices about gambling in society but in order to exercise choice we need to have an informed an informed decision-making process about whether or not to gamble.
Abstract: Jim Orford, Wiley-Blackwell, 2011, 282 pp., AUD$39.95 (paperback), ISBN 9780-470-66120-8 ‘We do have choices about gambling in society but in order to exercise choice we need to have an informed an...
50 citations
TL;DR: In this paper, the authors examined two Swedish replication prevalence studies (n = 10,000 and n = 15,000) with the aim of exploring evidence for a feminization of gambling in Sweden between 1997/1998 and 2008/2009.
Abstract: The study examines two Swedish replication prevalence studies (n = 10,000 and n = 15,000) with the aim of exploring evidence for a feminization of gambling in Sweden between 1997/1998 and 2008/2009 ...
TL;DR: In this article, the authors analyzed the social cost of gambling in Macao before and after the liberalisation of the gaming industry from a welfare economic perspective and identified seven principal items of social cost relating to gambling.
Abstract: This paper analyses the social cost of gambling in Macao before and after the liberalisation of the gaming industry from a welfare economic perspective. We identify seven principal items of social cost relating to gambling and, using data from 2003 and 2007, we calculate that the social cost of gambling in Macao rose by 163%, from US$40 million to US$106 million, during this period. We argue that this sharp escalation is the result of both the increasing gambling supply in recent years and the historical effect of the previous underdeveloped monopoly system. We acknowledge that our calculations are underestimations as a result of data limitation and we expect that the social cost of gambling in Macao will continue to rise in the coming years. Moreover, if the calculation is expanded to include the social costs incurred by tourists, the social cost of gambling in Macao should be much higher.
TL;DR: In this paper, the authors compared online pathological gamblers (OPG) and non-OPG in terms of gambling behaviour, socio-demographic features, psychopathology and personality characteristics.
Abstract: The purpose of this study was to compare online pathological gamblers (OPG) to non-online pathological gamblers (non-OPG) in terms of gambling behaviour, socio-demographic features, psychopathology and personality characteristics. A large sample of 1015 pathological gambling (PG) patients consecutively admitted to our Pathological Gambling Unit participated in the study. There were very few differences between OPGs and non-OPGs, limited to OPGs exhibiting slightly higher educational levels, higher socio-economic status and larger amounts of money spent on gambling and gambling debts. There were no differences in clinical, psychopathological and personality characteristics. Although some research has been conducted in the general population, the current paper is one of the few attempts to analyse this topic in clinical samples who seek treatment for their gambling problem. The lack of differences between OPGs and non-OPGs found in our study may encourage further studies to analyse whether similar therapy r...
TL;DR: In this paper, the first two waves of the Swedish longitudinal gambling study were used to study the prevalence of Internet gambling in 2008 and 2009 and the incidence in 2009, and the results indicated that a gender perspective on Internet gambl...
Abstract: In the present study, Internet gambling was studied with data from the first two waves of the Swedish longitudinal gambling study. Self-reported gambling problems, alcohol consumption, smoking, mental health, social support, gender and other socio-demographic factors were evaluated with respect to the prevalence of Internet gambling in 2008 and 2009 and the incidence in 2009. Multivariate logistic regression was used. In 2009 most Internet gamblers (72%) were men. However, women seem to have become more involved in Internet gambling. In 2009, 62.5% of new Internet gamblers since 2008 were men. Mental health, alcohol, smoking and social support were not predictive factors for incident Internet gambling. Self-reported gambling on regulated Internet sites showed higher prevalence rates of problem gamblers than gambling on land-based forms in 2008, but not in 2009. At both time-points, unregulated sites had the highest rates of problem gambling. The findings suggest that a gender perspective on Internet gambl...
TL;DR: The authors found that younger male, non-problem gamblers were most approving of the activity and that gambling and public policy are misaligned to the extent that gambling's harms are thought to outweigh its benefits.
Abstract: Albertans representing five age cohorts (13–15, 18–20, 23–25, 43–45 and 63–65) were surveyed (n = 1809) to assess their attitudes toward gambling in general, gambling in Alberta and legal gambling's impacts in the province. Age, gender and problem gambling status were found to be reliable predictors of gambling attitudes in that younger male, non-problem gamblers were most approving of the activity. Results also indicate that Albertans are ambivalent about gambling and that gambling and public policy are mis-aligned to the extent that gambling's harms are thought to outweigh its benefits. Likely reasons for the gap between gambling policy and public opinion are that gambling issues lack the salience of ongoing high-profile topics such as the economy, health care, education and the environment, and gambling dependent special interest groups can exert considerable influence on gambling policy in ways that may not harmonise with the public interest.
TL;DR: There are many contexts in which money can carry with it the stains of how it was acquired as mentioned in this paper, such as money acquired from the sale of illicit drugs, which is referred to as dirty money.
Abstract: There are many contexts in which we acknowledge that money can carry with it the stains of how it was acquired. For example, funds acquired from the sale of illicit drugs are referred to as ‘dirty ...
TL;DR: The authors used a negative feedback model to describe why pathological gamblers (PGs) spend more resources than non-pathological gamblers during a video lottery terminal (VLT) gambling session.
Abstract: This study used a negative feedback model to describe why pathological gamblers (PGs) spend more resources than non-pathological gamblers (NPGs) during a video lottery terminal (VLT) gambling session. Quantitative and qualitative data were collected via face-to-face semi-structured interviews with 43 PGs and 38 NPGs concerning their time and money management habits for gambling. Results show that the majority of PGs and NPGs use a monetary loss limit as a self-control strategy to avoid overspending. PGs, however, set a higher limit than NPGs. In addition, whereas NPGs typically stop gambling after having reached their limit, PGs typically keep spending their limited resources. To describe the self-regulation process during a gambling session, we propose an operationalization of self-control based on internal, external, implicit and explicit limits. The usefulness of a limit-based conceptualization of self-control for prevention and research is discussed.
TL;DR: The Personal Luck Usage Scale (PLUS) as discussed by the authors is a psychometrically sound measure for personal luck and its sequelae among gamblers, which has been developed to understand personal luck.
Abstract: Luck is by definition a random event. However, many people believe luck to be something it is not – an internal, personal quality. An obstacle for understanding personal luck and its sequelae among gamblers has been the lack of a psychometrically sound measure. The current paper reports the development of the Personal Luck Usage Scale (PLUS). In Studies 1 and 2 (Ns = 347 and 361, respectively), a one-dimensional, eight-item scale emerged and was subsequently confirmed among university-aged gamblers. Importantly, the PLUS was distinguishable from a general belief in luck (Study 2). In Study 3 (N = 60), a behavioural consequence of belief in personal luck was assessed among a community sample of gamblers. Specifically, PLUS scores were positively associated with the average amount of money spent in a gambling session. The implications of a belief in gambling-related personal luck for the progression and maintenance of problem gambling are discussed.
TL;DR: The proposed DSM-V diagnostic criteria for pathological gambling within the DSM suggest removing the criterion of committing illegal acts and reducing the threshold to four symptoms as mentioned in this paper, which has been argued that changing the diagnostic criteria will not impact the prevalence rate of pathological gambling.
Abstract: The proposed revision of the diagnostic criteria for pathological gambling within the DSM suggests removing the criterion of committing illegal acts and reducing the threshold to four symptoms It has been argued that changing the diagnostic criteria will not impact the prevalence rate of pathological gambling, however there are no published studies examining prevalence rate stability The impact of the proposed DSM-V criteria using data from a national study assessing gambling behaviors among college student-athletes was examined Comparison of pathological or disordered gamblers vs sub-threshold gambling severity using current DSM-IV criteria and the proposed DSM-V diagnostic criteria suggests that the proportion of men classified as pathological or disordered gamblers changes For females, comparisons did not reach statistical significance The subcommittee of the DSM-V should note that the proportion of males meeting the diagnostic criteria for pathological gambling may be influenced by classification
TL;DR: In this paper, an exploratory analysis of the gambling typologies and profiles of Canadians based on game frequency and preferences through latent class analysis, using a nationally representative Canadian Community Health Survey (CCHS 1.2).
Abstract: Similar to many other countries, Canada has witnessed a growing concern over gambling problems population and the potential for related negative consequences. Research results thus far highlight the heterogeneity of the problem gamblers and suggest game preferences may distinguish gambler types. This study entails an exploratory analysis of the gambling typologies and profiles of Canadians based on game frequency and preferences through latent class analysis, using a nationally representative Canadian Community Health Survey (CCHS 1.2). The results showed that the survey respondents could be partitioned into eight latent classes/subtypes that represent distinct gambling profiles. The classes could be ordered with respect to the extent to which class members are affected by an increased prevalence of gambling problems with marked differences between the classes in terms of their demographic makeup. The ordering of classes and its correspondence to problem gambling severity supports the notion of a problem ...
TL;DR: This paper provided an examination of the Court of Appeal decisions in England and Wales from January 2000 to January 2009 drawing on the original cases and appeals, and concluded that although judges recognised problem gambling as a condition, problem gambling did not appear to be accepted as a factor explaining the commission of the crime in English and Wales.
Abstract: Previous research indicates that problem gambling is often associated with crime. Most of this research is focussed on individual psychological cases or data sets examining the relationship between crime rates and location of gambling venues. There is little international research on the response of criminal courts in recognising and accepting problem gambling as a reason for committing crime. This paper provides an examination of the Court of Appeal decisions in England and Wales from January 2000 to January 2009 drawing on the original cases and appeals. The findings of this research are relevant to an international audience where problem gambling is dismissed as a reason for committing crime when facing sentence. It was concluded that although judges recognised problem gambling as a condition, problem gambling did not appear to be accepted as a factor explaining the commission of the crime in England and Wales.
TL;DR: In this paper, the authors examined factors influencing vendor compliance with minimum-age legislation to better understand how underage youth acquire lottery products and found that only a moderate proportion of vendors were compliant with existing statutes.
Abstract: Despite legal prohibitions to restrict the availability of lottery products to minors, research shows a high prevalence of lottery playing among adolescents. This study examined factors influencing vendor compliance with minimum-age legislation to better understand how underage youth acquire lottery products. To provide perspective, accessibility to lottery products and alcohol was compared. Six under-age youths (three males, three females; mean 15.8 years) each attempted to purchase a scratch card, a beer, or both products in a sample of convenience stores (494 purchase attempts). Results revealed that only a moderate proportion of vendors (60%) were compliant with existing statutes. The gender of the purchaser and vendor, and the type of store were found to be significant in the prediction of youths’ ability to purchase controlled products. Results suggest possible mechanisms involved in the compliance or noncompliance with regulations, and imply considerations for awareness-raising among vendors in terms of controlled products.
TL;DR: In this paper, the authors proposed that problem gambling may be a consequence of a low-K life history strategy and that by using evolutionary theory they can enhance our understanding of problem gambling, by linking it to a broader the...
Abstract: Evolution has created a spectrum of life history strategies that are linked to different personality profiles. People with low-K life history strategies display traits such as low parental investment, non-adherence to social rules, short-term planning, risk taking and impulsivity. We hypothesized that low-K strategists, who are characterized by this personality profile, would be inclined towards problem gambling. Seventy male customers of Israeli kiosks that offer lottery tickets answered questionnaires about their gambling behaviour, personality traits and demographics. As hypothesized, customers who came to buy a lottery ticket had lower K strategies than other customers. In addition, customers with a lower K strategy tended to report higher levels of problem gambling, independent of demographics. We propose that problem gambling may be a consequence of a low-K life history strategy and that by using evolutionary theory we can enhance our understanding of problem gambling, by linking it to a broader the...
TL;DR: In this paper, a discussion about 170 editorial cartoons from the Finnish print media, from 1961 to 2005, shows how the cartoons profile the Finnish gambler and what emotions are associated with gambling.
Abstract: How do editorial cartoons represent gambling? What can visually oriented thinking give to gambling research? The answers are rooted in the expanding research about visual culture, methodologies and data in social sciences and cultural studies The discussion about 170 editorial cartoons from the Finnish print media, from 1961 to 2005, shows how the cartoons profile the Finnish gambler and what emotions are associated with gambling The discussion then turns to Finnish gambling culture and gambling's role in society Space, communication, power relations, and the use of gambling as a political metaphor are highlighted The assessment demonstrates the value of popular-cultural data for gambling studies The examination complements the existing cartoon research and visual-cultural studies and has interdisciplinary pedagogical potential
TL;DR: Cheng et al. as discussed by the authors reviewed TJ Cheng's 'The Sociology of Gambling in China', Beijing: Social Sciences Academic Press ; Reading. UK: Paths International, 2011
Abstract: Book review of TJ Cheng's 'The Sociology of Gambling in China', Beijing: Social Sciences Academic Press ; Reading. UK: Paths International, 2011
TL;DR: Interactive gambling in all its forms (computers, smartphones, wireless devices and, to a lesser extent, interactive television) is revolutionizing the delivery of gambling products as discussed by the authors.
Abstract: Interactive gambling in all its forms (computers, smartphones, wireless devices and, to a lesser extent, interactive television) is revolutionizing the delivery of gambling products. Substantial ch...
TL;DR: A sociological perspective on recreational, excessive and problem gambling with an emphasis on the role of all stakeholders, including communities, gambling venues and operators and regulators is presented in this article.
Abstract: This book offers an interesting sociological perspective on recreational, excessive and problem gambling with an emphasis on the role of all stakeholders, including communities, gambling venues and operators and regulators. The chapters include an extensive, up-to-date review of international gambling research, global gambling and gambling regulation. The latter half of the book describes two research studies conducted in Australia that explored gambling experiences among youth and pathways to excessive gambling in adults. A key strength of this book is its use of evidence throughout the chapters to support claims and assertions and to explore how gambling impacts individuals, families and the wider community. The first half of the book gives an extensively detailed introduction to the global gambling situation. Existing gambling research is comprehensively analysed to highlight strengths, weaknesses, challenges and limitations. This review includes research on all gambling without falling into the trap of focussing exclusively on problem gambling, a tendency that is often characteristic of the field. The sociological approach taken is refreshing and offers an interesting perspective that includes individual and environmental factors in relation to gambling and problem gambling. The review of the state of global gambling is similarly ample covering each major form of gambling. Statistics, figures and evidence are included from international sources on expenditure, accessibility, prevalence, participation, regulation, responsible gambling, advertising and problem gambling. The focus of the book then turns to Australia, providing a context for the subsequent studies and other research emerging from this jurisdiction. This chapter provides a useful background for understanding the recent Productivity Commission inquiry into gambling and subsequent recommendations. The first four chapters would prove extremely useful for individuals entering the field, or wishing to be brought up-to-date on the current state of the field without consulting multiple sources. The review is unbiased and apolitical. The chapter on youth gambling presents the results of a survey undertaken in 2000 in Australian regional and rural communities. The 754 respondents, aged between 14 and 25 years of age, answered questions about gambling as well as their overall leisure activities, their community belonging and future aspirations. As the research was conducted over 10 years ago this must be recognised as a limitation given that the state of gambling in Australia has changed considerably since that time. Of particular note is the emergence of Internet and remote gambling opportunities, forms expected to be of importance in geographically isolated communities. Nonetheless, the data is still of interest and is well presented and analysed. The evidence presented regarding adult’s excessive gambling pathways adopts a qualitative approach. A series of case studies are analysed based on clients presenting for treatment at a multicultural problem gambling service in New South Wales, collated in
TL;DR: In this paper, the authors used mathematical analysis to derive more accurate approximation formulas for computing the rebate rate on actual loss in the VIP gaming market, and discussed how these two rebate systems affect the fluctuations of the results.
Abstract: In Macao, the VIP gaming revenue accounts for over two thirds of the total gaming revenue. Since the VIP gaming market is highly competitive, several incentives such as rebates are used to attract the VIP players. There are two commonly used rebate systems in the VIP gaming market: rebate on buy-in and rebate on actual loss. The analysis of rebate on buy-in is relatively easy. However, the analysis of rebate on actual loss is more complicated, which involves the Unit Normal Linear Loss Integral. Using empirical data, MacDonald derived a simple approximation formula for computing the rebate rate on actual loss. In this paper, we use mathematical analysis to derive more accurate approximation formulas for computing the rebate rate on actual loss. Some practical examples are given to compare the accuracies of these formulas. We also discuss how these two rebate systems affect the fluctuations of the results.