Setting the Record Straight
Posted: May 7, 2009
Anyone who follows the U.S. commercial casino industry in the news is familiar with gaming critics’ well-worn claim that living in close proximity to casinos leads to an increase in disordered gambling – a claim often used as a key argument against gaming expansion.
To bolster their argument, opponents frequently cite a statistic from a National Opinion Research Center (NORC) study, which was submitted to the congressionally mandated National Gambling Impact Study Commission in 1999. According to the study, prevalence rates of pathological and problem gambling double within a 50-mile radius of a casino.
This may seem like a reasonable assertion. But, after close inspection of the NORC study’s deeply flawed methodology, it cannot be accepted as a valid conclusion.
In fact, a report developed for the European Commission – the executive branch of the European Union – undermines the entire NORC study. In particular, it impeaches the oft-cited proximity finding, which was identified only after combining results from various data samples.
Published in 2006, the report for the E.U. highlights the NORC study as an example of how political considerations can influence research on problem gambling. It explains:
"Under pressure from the National Gambling Impact Study Commission, NORC increased the sample size of problem and pathological gamblers, and supplemented their sample with an intercept sample of gambling facility patrons, stratified by lottery and non-lottery states and at various gaming facilities in the United States. But this was not a random sample (equally likely to be selected) of households… Intercept samples are not truly random and do not have well-defined statistical properties; it is therefore not possible to draw valid general conclusions for the population from their results…
Nonetheless, NORC combined the intercept sample, conducted to “find” more problem and pathological gamblers, with the RDD (random digit dial numbers) sample and used the combined sample for analysis. This procedure is fatally flawed since the patron survey was not a truly random sample as was the RDD sample. All of the care taken to assure an unbiased random sample using the RDD method was negated when the two samples were combined…
Unfortunately, even though they acknowledged the problems with the merged sample, the NORC team still proceeded to analyze the results of the survey with respect to pathological and problem gambling. However, the results of their analysis with respect to problem and pathological gambling are not valid in terms of their ability to generalize to the target population, and therefore should not be used in research or policy analyses."
In other words, by combining a limited, biased sample with a random sample, the NORC study’s conclusions were tainted. And yet, despite the report’s faulty methodology, its findings – particularly the proximity statistic – have been widely circulated by gaming opponents in hundreds of reputable news sources.
In reality, the rate of gambling disorders does not necessarily increase within a 50-mile radius of a casino. A recent study published in Psychology of Addictive Behaviors last June found that prevalence rates of pathological gambling are not higher near a casino than they are farther away from it.
Similarly, a 2007 research report from Harvard studied what’s known as the adaption effect. It found that, while problem gambling rates may briefly increase with the introduction of gaming into a community, those rates return to a normal level in a short period of time.
And, ultimately, despite tremendous industry growth and expansion, the prevalence rate of disordered gambling has remained virtually unchanged over the past 30 years. Countless peer-reviewed research studies have found that approximately 1 percent of adult Americans are pathological gamblers, and recent reports indicate prevalence rates may be even lower.
The commercial casino industry takes disordered gambling extremely seriously and is committed to addressing the issue by educating its employees and patrons about how to gamble responsibly and assisting those who cannot control their gambling in finding the help they need. But members of the media can no longer be complicit in spreading bad information based on faulty research. It is time to set the record straight – once and for all.
