The meaningfulness of New York City’s new A-B-C letter grade restaurant inspection rating system seems suspect when the Times’ FiveThirtyEight blog crunches the numbers:
As it currently stands, though, the grading system is too coarse, because it masks wide variations in the quality of restaurants receiving the same grade, making it hard to say quite what it means to be an A-rated restaurant in New York City. Closer inspection of the underlying data reveals a suspicious distribution of restaurants near the cut-off point between an A and a B.
. . .
During this period, only 381 restaurants scored a perfect zero, while 1,012 scored 12 points and 721 scored 13 — just barely squeaking in to the A category. The data suggests that when you visit an A-rated restaurant, the odds are that it barely made the grade.
A more pressing statistical problem arises from the sharp break in the 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.
. . .
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.
And if you wondered why it seems that you only see A grades at the restaurants you pass by, here’s why:
Posted: January 20th, 2011 | Filed under: Things That Make You Go "Oy"
If you’ve strolled past any New York City restaurants lately, you might have noticed new window placards with letter grades staring out at you. You might have also noticed, “A’s” are much more common than “C’s.”
. . .
NBC New York examined records for all six-hundred-fifty Manhattan restaurants that have scores of 28 or above, and only seventy-six are currently posting a “C” grade. That means 88% of the borough’s poor-scoring restaurants are currently avoiding the “C” label.
The reason for the delay in posting appears to be a lengthy re-inspection and appeals process that restaurants can take advantage of. If a restaurant does not score an “A” on its first inspection, it can wait up to four weeks for a re-inspection. If the second inspection score is still too high for an “A,” the eatery can appeal to the department’s Administrative Tribunal. Sources say if a restauranteur takes advantage of adjournments, he or she can stall the grading process for up to five months.