GLOBAL: Global advertising expenditure is expected to maintain steady growth in 2017 despite the uncertainty triggered by the US presidential election and the UK's referendum on EU membership, according to a series of new agency forecasts.

Both WPP's GroupM and Publicis Media's Zenith reported that they expect global adspend to increase 4.4% next year – although differing methodologies meant their overall totals came out at $547bn and $566bn respectively.

Meanwhile, Interpublic Group's Magna has forecast that adspend growth will slow to 3.6% in 2017, bringing in advertising revenues of $511bn, MediaPost reported.

All the reports pointed to the rapid growth of digital and social adspend, with GroupM noting that digital's share is expected to reach a third (33%) of all advertising in 2017, when digital is forecast to take 77 cents of every new ad dollar while TV captures 17 cents.

Magna reported that digital grew 17% globally to $178bn in 2016 and also predicted that it will account for at least half of global adspend ($299bn) by 2021, when linear TV is expected to account for a third ($195bn).

And Zenith forecast that global adspend allocated to social media will grow 72% between 2016 and 2019, rising from $29bn to $50bn.

Social media advertising currently accounts for 16% of all internet advertising, Zenith added, but its share is expected to climb to a fifth (20%) in 2019.

Interestingly, that means social media adspend is on course to be worth just 1% less than newspaper advertising in 2019, and it is expected to be comfortably ahead by 2020.

"For many users, social media is the focal point of their social lives as well as their main source of news," Zenith explained. "Social media ads blend seamlessly into the news feed, and are much more effective than interruptive banner formats, especially on mobile devices."

Zenith went on to highlight the growth of online video advertising, which it said is rising almost as quickly as social media advertising.

Global online video adspend is expected to total $35.4bn by 2019, or a little more than the expenditure dedicated to radio advertising ($35bn).

"Social media and online video are driving continued growth in global adspend, despite political threats to the economy," said Jonathan Barnard, Head of Forecasting at Zenith.

The agency outlooks are in line with Warc's latest Consensus Ad Forecast, a weighted average of predictions from various sources including the aforementioned, which anticipates a 4.2% rise in global advertising expenditure during 2017.

Data sourced from GroupM, Zenith, MediaPost; additional content by Warc staff