The results of re-weighting PMB 2004 to match Statistics Canada 2001 Census data caught some industry researchers by surprise – and they are now alerting company planners and buyers to watch for large high-income readership increases due to changes in the universe measured.

Tim Wilson, VP research at MediaCom Group Services (Media Buying Services, The Media Company, and Retail Media) of Toronto, says PMB’s re-weighting, which increases the number of households in the $100,000-plus income category from 8% to 13% of total households for 2004 (2001 Census data pegs it at 12%), had a strong impact on the readership results.

He says the changes are so significant, he’s cautioning planners and buyers to watch for publications that might try to make their readership increases within this attractive demo a key selling point.

Wilson emphasizes that the 2004 study is not a change in PMB methodology but rather a change in the population.

‘It totally makes sense for PMB to do what it did because it is so important to its members – the publishers and the buyers – that the income is really nailed down in this study. From our point of view, PMB is still the gold standard because it is the only [media measurement organization] that does weight by income.’

To counterbalance, Wilson is suggesting that MediaCom Group planners and buyers look at a publication’s percentage of coverage within selected demographics rather than actual readership numbers.

Wilson observes, ‘Comparing on a percentage-of-coverage basis equalizes the change in the universe. For example, Maclean’s had 8% coverage of the 25-to-54, $100,000-plus income before [2003], now they still have 8% coverage – it’s only that the universe itself has changed, while their percentage of coverage against it is still the same.’

David O’Neill, MediaCom Group research manager, alerted Wilson to the rather dramatic rise in readership, which he found when running an analysis of PMB data against the high-income demos that make up the target group for many of the agency’s clients.

The adjustment from the 1996 Census data used in PMB 2003 to the 2001 Census used in PMB 2004 reflects a real 73% increase in the number of households making more than $100,000, a rise from 8% to 12% of total households.

Steve Ferley, president of PMB, says every annual PMB release is updated using the most current census information as well as ‘intercensal’ – or between census – data for most of the demographics.

Each year, changes in age, gender, province, and size of major cities are factored in. For the 2004 PMB results, household income, household size, household composition, and language were also considered.

‘We don’t simply move from 1991 to 1996 to 2001 census,’ notes Ferley. ‘We use gradations between those censuses. We keep track of a growing population year by year by year. It doesn’t just hiccup upwards; it goes upwards every single year with intercensal information.’