The paragraph is followed by an incomplete phrase or sentence which summarizes the main idea of the paragraph. Choose the missing words of the phrase or sentence.

Over the past several decades, most industrialized countries have experienced a substantial drop in the average age at which individuals retire from the labour market. Longer life expectancy and better health have not been accompanied by longer working lives. As a consequence, these countries are facing serious concerns about the viability of social security systems.
Earlier （） of people.