Since the late '70s, the economy has been changing. It's kept growing on the whole, but the benefits of that growth have been increasingly unevenly distributed. In particular, the share of the benefits going to wages (ie earnings for ordinary working people) has declined sharply, as shareholder profits have taken a bigger and bigger slice of the pie.
You can use our incomes tracker to see what you might be earning today, had wages for your job had the same economic share as they had in the 70s.
NB: This tool makes a calculation based on the economic quintile your earnings put you in, as wages for different jobs have kept their value to different degrees. This means we're only able to give you a rough figure (especially if your salary falls into the highest quintile). We ask for 2010 salary rather than 2011 as official statistics haven't quite caught up yet for us to calculate.