The number of jobs in ad agencies has declined for the first time since 1992, according to the annual survey by the Institute of Practitioners in Advertising. As at 1 September 1997, 12,700 hardy souls earned their living in IPA member agencies - 100 less than the previous year. The survey also shows that the industry is dominated by the young, with over half of all staff still sucking their thumbs while awaiting the big three-O.