• by Erik Sass  @eriksass1, May 13, 2011

The controversy over ratings from Arbitron's Portable People Meter, a passive electronic measurement device, may have abated, but PPM's impact on the radio business is still being worked out.

Radio One President Barry Mayo told Radio Ink that PPM ratings were to blame for revenue declines in key markets, including Cincinnati, Columbus, Cleveland and Indianapolis.

According to Mayo, Radio One's ratings took a big hit following Arbitron's switch from paper diaries to PPM measurement, which in turn, has depressed Radio One's ad sales. The ratings declines ran as high as 50% in Indianapolis, Radio Ink reports.

Radio One's net radio revenues sank 1.5% in the first quarter of 2011 compared to the same period in 2010, although this was offset by growth in its TV business, TV One.

In its 10-K filing to the SEC for 2010, Radio One noted the negative impact of PPM ratings on its business -- identifying this as a potential risk factor for investors -- but didn't say whether it views these ratings as inaccurate.

Mayo and Radio One CEO Alfred Liggins III were similarly circumspect in their latest statements. It's worth noting that in the past, Liggins has defended PPM against criticism from other minority radio broadcasters. However, he also criticized "wild swings" in ratings when PPM was first introduced in the Houston market in 2007.

The question of accuracy is central to PPM's legitimacy as a currency for buying and selling radio ad inventory.

Minority broadcasters in particular have taken exception to PPM ratings in the past, saying that inconsistent and incomplete sampling methodology led to large apparent drops in their audience sizes. The issue became so contentious that Congress scrutinized Arbitron's methodology and heard testimony from witnesses representing Arbitron, minority broadcasters and the Media Rating Council, which is responsible for granting accreditation to media ratings systems.

The high-profile controversy seemed to be resolved last year, with Arbitron promising to improve its minority sampling methodology and minority broadcasters joining the MRC to gain more access to information about what goes into PPM ratings.

However, as the Radio One statements made clear this week, the long-term impact of PPM on minority broadcasters is still very much up in the air.