Today's inaugural World Inequality Report shows that income inequality has increased in nearly every country around the world since 1980 - but at very different speeds. Since [1980], the gap between the richest and the rest has surged in the US, while in western Europe it has increased only moderately. In both regions, the top 1% of adults earned about 10% of national income in 1980. Today that cohort's share has risen modestly to 12% in western Europe, but dramatically to 20% of all income in the US. The good times have rolled especially fast for those at the very top in the US, with annual income booming by 205% since 1980 for the top 1%. But this boomtime at the very top has not benefited the rest of the American population in any measurable way. For the 117 million American adults in the bottom 50%, income growth has been nonexistent for a generation. In western Europe, by contrast, incomes of the bottom half have matched overall economic growth. What explains this dramatic divergence? The US has experienced a perfect storm of radical policy changes. The tax system, which used to be progressive, has become much less so over time. The federal minimum wage has collapsed, unions have been weakened and access to higher education has become increasingly unequal. At the same time, deregulation in the finance industry and overly protective patent laws have contributed to booms on Wall Street and in the healthcare sector, which now makes up 20% of national income.