The squeezed middle

is the new expression (or buzz word) in English. It is a noun and refers to people on average incomes who have less money than previously to buy the things they need because rising costs have not been matched by an increase in pay: 

'Many of these companies have built their brands on the backs of the country's middle-classes. But this swathe of society, caught between recession-proof top earners and low-income households, has come to be described as the squeezed middle in modern-day, austerity Britain.'
Wall Street Journal 8th October 2012

At MacMillan dictionary we have more info on this new concept which came up in 2011. Can you tell us what it means with your own words? Is that happening in Spain as well?