IN THE MID-70s and 1980s, football started to become very unfashionable. In some quarters, you were almost embarrassed to say you were a regular fan. You couldn’t give away tickets at some clubs. And it was still relatively cheap to watch the game. In 1975, a ticket at a First Division game was around £ 1.50 – that represented 6.5% of the weekly wage. In 2013, a seat at the Emirates Stadium for an Arsenal Premier League game could cost £50 – 13% of the weekly wage.  So, in relative terms, football is twice as expensive as it was 40 years ago. If you adopt the law of supply and demand, football doesn’t need to concern itself too much. In 1975-76, the average first…