Philadelphia PPM In-Tabs Crater

Inside Radio reports today that the Philadelphia April PPM in-tabs reached their lowest level in eight months. The second week of April, total 6+ in-tab was 1,524. Arbitron's target is 1,530. The company has argued that declines were inevitable as they worked to increase 25-34 sample. While 25-34 has increased from 141 persons to 167, a gain of 26, total in-tab has declined 292 persons.

Despite an MRC requirement that standard error information accompany all ratings reports, Arbitron has yet to publish any data that would tell us what kind of reliability we get with these cell sizes. Given the big rating swings we've seen,  margins of error are probably pretty large.