The OECD defines the middle class in economic terms of people earning 75% to 200% of the national median annual income. Within OECD nations incomes have increased 0.3% on average per year versus growth of 1.6% and 1% in the proceding decades. Housing costs now amount to a third of their disposable income which is up by 25% since the 1990’s. But in most countries this erosion isn’t only growing the lower class but simultaneously rising the upper class.
