Until protesters took to the streets last year, first in New York and then in financial centres across the world, inequality had been a low-key issue.
Not any more.
With the political temperature rising, a stream of new analysis is revealing how sharply inequality has been growing.
In October, the US Congressional Budget Office (CBO) caused a storm by revealing how big a slice of income gains since the late 1970s had gone to the richest 1% of households.
The message was dramatic.
Over the 28 years covered by the CBO study, US incomes had increased overall by 62%, allowing for tax and inflation.
But the lowest paid fifth of Americans had got only a small share of that: their incomes had grown by a modest 18%.
Middle income households were also well below the overall average with gains of just 37%.
And even the majority of America’s richest households saw gains of barely above the overall average at 67%.
How does that make sense?
Because the CBO found most of the income gains over the past 30 years had gone to the top 1% of US households. Their incomes had almost trebled with rises of 275%.