Rising economic inequality in the United States has become a central issue in the race for the Democratic presidential nomination, and discussions about policy interventions that might help address it are likely to remain at the forefront in the 2020 general election.

As these debates continue, here are some basic facts about how economic inequality has changed over time and how the U.S. compares globally.

1) Over the past 50 years, the highest-earning 20% of U.S. households have steadily brought in a larger share of the country’s total income. In 2018, households in the top fifth of earners (with incomes of $130,001 or more that year) brought in 52% of all U.S. income, more than the lower four-fifths combined, according to Census Bureau data.

In 1968, by comparison, the top-earning 20% of households brought in 43% of the nation’s income, while those in the lower four income quintiles accounted for 56%.

Among the top 5% of households – those with incomes of at least $248,729 in 2018 – their share of all U.S. income rose from 16% in 1968 to 23% in 2018.

2) Income inequality in the U.S. is the highest of all the G7 nations, according to data from the Organization for Economic Cooperation and Development. To compare income inequality across countries, the OECD uses the Gini coefficient, a commonly used measure ranging from 0, or perfect equality, to 1, or complete inequality. In 2017, the U.S. had a Gini coefficient of 0.434. In the other G7 nations, the Gini ranged from 0.326 in France to 0.392 in the UK.

Globally, the Gini ranges from lows of about 0.25 in some Eastern European countries to highs of 0.5 to 0.6 in countries in southern Africa, according to World Bank estimates.

3) The black-white income gap in the U.S. has persisted over time. The difference in median household incomes between white and black Americans has grown from about $23,800 in 1970 to roughly $33,000 in 2018 (as measured in 2018 dollars). Median black household income was 61% of median white household income in 2018, up modestly from 56% in 1970 – but down slightly from 63% in 2007, before the Great Recession, according to Current Population Survey data.

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