America’s teenage population is slowly falling (the US Census Bureau says it peaked at 26m a few years ago) and summer-time youth unemployment is at its highest level (19.1%) in more than 60 years, according to figures from the US Department of Labor. Despite this, the US market for products bought by and for teens, now worth about $200bn (£125bn) a year, is still growing and will reach nearly $210bn (£131bn) in 2011, according to market research firm Packaged Facts.