No. of middle-income households growing in US: Pew Research

After more than four decades of serving as the nation's economic majority, the American middle-class is now matched in number by those in the economic tiers above and below it, says Pew Research Center.

In early 2015, 120.8 million adults were in middle-income households, compared with 121.3 million in lower- and upper-income households combined, a demographic shift that could signal a tipping point. The middle class made up 50 per cent of the U.S. adult population in 2015, down from 61 per cent in 1971.

In at least one sense, the shift represents economic progress: While the share of U.S. adults living in both upper-income (21 per cent today) and lower-income (29 per cent) households rose alongside the declining share in the middle from 1971 to 2015, the share in the upper-income tier grew more. In 2015, 20 per cent of American adults were in the lowest-income tier, up from 16 per cent in 1971.

On the opposite side, nine per cent are in the highest-income tier, more than double the four per cent share in 1971. Meanwhile, the shares of adults in the lower-middle or upper-middle income tiers remained unchanged.