Why is this finally happening? The answer involves a fortuitous mix of policy changes and ongoing economic growth.

“The two leading factors are the tightening labor market and the state-level minimum wage increases,” said Elise Gould, a senior economist at the left-leaning Economic Policy Institute. Labor protests like the Fight for $15 movement contributed to minimum-wage increases in several states and cities. The impact has been obvious: Wages for the poorest 10 percent grew two-times faster in states with minimum-wage increases.

Minimum-Wage Increases Spurred Wage Growth for Americans Earning in the 10th Percentile

But wage growth for the poor ticked up even in states without minimum-wage hikes. That’s because a falling unemployment rate is especially critical for pushing up wage growth for the poor. With each percentage-point fall in unemployment, it’s the bottom decile that sees the most wage growth.

There are some easy lessons here. First, low unemployment is a low-income worker’s best friend. Second, in the last two years, minimum-wage hikes raised income for the poor without, it seems, destroying jobs or raising the unemployment rate. Third, the U.S. economy seems capable of producing broadly shared income growth, at least late into a recovery cycle, despite the many well-founded fears that rich, educated workers are leaving their poorer, less-educated peers in the dust.

What nobody can say, however, is whether this happy trend is durable. Will a recession strike and wipe out these gains for the poor? Will minimum-wage increases prove to be a one-off moment of income growth for the poor? Will higher wages for low-skill workers ultimately accelerate the automation of their jobs, since employers get more labor savings from replacing an expensive job than a cheap one?

Nobody knows. But for now, wage growth for the poor is the happiest story nobody is talking about.