Mr. Mitchell, 51, strategic affairs director at Guinness, takes the WFA helm from Hans Merkle, Procter & Gamble Co. director of external affairs in Germany.
Mr. Mitchell said other key issues that need attention are developing effective self-regulation, avoiding anti-advertising legislation and communicating better "the economic case for advertising in the political arena."
"I think as media get more complicated, the skills required in the marketing area are removed from the skills of people today," Mr. Mitchell said. "As P&G is saying, maybe 10 years from now we won't be using TV advertising."
He said a major change is the disappearance of the marketing director, like the brand manager became passe earlier.
Mr. Mitchell cited Unilever as an example of a company that has redefined the role of its senior marketing people, a move he said other companies are likely to follow.
The WFA membership consists of 35 national advertiser associations and 29 international companies. The group is also seeking a replacement for Paul de Win, the director-general based at WFA headquarters in Brussels. He is to retire next spring.