distribution that occurs around the grade cut-off point. Keep in mind that the 13-point threshold is somewhat arbitrary; there is likely to be little difference between a restaurant with 13 points worth of violations and one with 14 points.
Take a look, though, at the number of restaurants whose scores barely qualified for an A, and those whose scores just missed. Four times as many restaurants scored 11, 12 or 13 than scored 14, 15, or 16.
There are at least two possible explanations for this unusual distribution. One has to do with a provision of the system that allows non-“A” restaurants to request a re-inspection in hopes of earning a better score, and to hang a “Grade Pending” sign in their windows in the meanwhile. The spike in restaurants with 11, 12, or 13 points could be the result of restaurants with initial scores in the B range cleaning up their acts just enough to qualify for an A.
An alternative explanation could be related to the inspectors themselves. Knowing that restaurants that get B grades are likely to appeal them, inspectors may be more likely to rate a restaurants on the cusp with an A-range score; after all, the difference between 13 points and 14 is marginal, but the difference between an A and a B is meaningful. Given the subjective nature of the inspection process and the discretion that inspectors have to assign scores, the data suggest that inspectors may be disproportionately likely to assign restaurants a just-made-it A score than a just-missed B.
Given the current distribution of scores, what would happen if the cut-off for an A grade were to be raised slightly, to 12 or perhaps 11 or 10 points? Substantively, a difference of one or two points in a restaurant’s violation score is probably very small, but the shift in the number of A ratings would be quite significant.
Lowering the threshold for an A grade by one point would cut the proportion of restaurants earning an A by six percentage points, from 56 percent to 50. If it were lowered by two points, the percentage of A-rated restaurants would fall to 42 percent of the total — meaning that one-quarter of all restaurants now displaying an A would be downgraded to B.
The point is not to quibble over the cut-off point, but to acknowledge that switching the (seemingly) arbitrary threshold slightly results in a major change in our perception of how well restaurants are doing.
|Cut-off score||Share of restaurants graded A|
As an alternative to the coarse three-letter system currently used by the Department of Health, the graph below puts the current scores on the more familiar academic scale by subtracting each point in violations from a restaurant’s initial score of 100 percent. For example, a restaurant with 13 points in violation would score an 87 (100 − 13 = 87). As in a school setting, a score between 90 and 92 receives an A−; between 93 and 96, an A; between 97 and 100 receive an A+, and the B and C grades are broken down similarly. In addition to being more recognizable, a more nuanced grade system provides more precise information to consumers, and addresses the reality that not all A’s are equal.
Although the current grading scheme is imperfect, it does offer some consumer protection and ought to be applauded. According the Department of Health, tainted restaurant food accounts for more than 10,000 visits to the emergency room and 5,000 hospitalizations each year; providing customers with easy-to-access information may help them avoid joining those totals.
In rethinking the grade system, we should keep in mind that any grading systems necessarily involves arbitrary cutoffs. Publicly available information does not provide any rationale for 13 points as the cutoff for an A grade, and requests for explanation went unanswered by the Department of Health. The distribution of scores around the 13-point cutoff raises questions, but these questions should not lead us to abandon the system of scoring restaurants completely.