sentences:  However, much of the movement of households involves changes in income that are large enough to push households into different income groups but not large enough to greatly affect the overall distribution of income.Multi-year income measures also show the same pattern of increasing inequality over time as is observed in annual measures.In other words,many people who have incomes greater than $1 million one year fall out of the category the next year – but that's typically because their income fell from, say, $1.05 million to .95 million, not because they went back to being middle class.Disagreements about the correct procedure for measuring income inequality continues to be a topic of debate among economists, including a panel discussion at the 2019 American Economic Association annual meeting.Several studies found the ability of children from poor or middle-class families to rise to upper income – known as "upward relative intergenerational mobility" – is lower in the US than in other developed countries.