Warc's Consensus Ad Forecast is based on a weighted average of adspend predictions at current prices from ad agencies, media monitoring companies, analysts, Warc's own team and other industry bodies.
A net growth in adspend in 2015 is predicted for 12 of the 13 markets covered – including Australia, Brazil, Canada, China, Germany, India, Italy, Japan, Russia, Spain the UK and the US – with only France contracting slightly.
Overall, the rate of growth has been revised downwards for nine countries since the last Consensus Ad Forecast in July 2014. At the same time, total forecast global adspend for 2015 has been raised 0.1pp since then.
BRIC countries will be the strongest performers this year, with India, China and Brazil expected to see all-media growth of 11.6%, 10.3% and 7.1% respectively.
Russia, however, has seen the single largest downgrade in expectations from the previous report, from 8.5% to a mere 1.4% as political and economic uncertainties take their toll.
The UK is forecast to show the fourth-largest growth rate this year at 5.7%, unchanged from July, while Spain was revised upwards by 1.2pp to 4.5%.
Of the remainder, only the US (+3.5%), Canada (+3.4%) and Australia (+2.7%) are expected to grow faster than 2% in 2015.
In terms of media, all except newspapers and magazines are predicted to record year-on-year growth in 2015, with Internet seeing the greatest increase, up 16.0%.
Newspaper is the only channel for which forecasted growth has been upgraded since July, although a rise of 1.2pp leaves it shrinking a slower rate of -3.6%.
TV, meanwhile, has seen the largest downgrade – by 2.7pp – with growth this year now expected to come in behind Cinema (4.0%) and Out of home (3.9%).
"The global economic outlook is more uncertain than six months ago, with eurozone stagnation, Russian sanctions and a slowdown in Asia all threatening growth," said James McDonald, research analyst at Warc. "It is therefore unsurprising that many market-watchers, including us, have revised down expectations.
"Despite the uncertainty, we should still see growth in global advertising expenditure of between 5% and 6% this year and next."
Data sourced from Warc