The trendline for the Gini Coefficient has been linear since before Reagan took office, so I’m not sure where you got the notion of a ‘spike’.
If you look at the underlying numbers, the issue of economic inequality is primarily related to the bottom of the curve rather than the top. This problem is often referred to as ‘generational poverty’, where certain groups are mired in seemingly inescapable poverty.
The causes of this can be debated, but it’s likely due to diminished opportunities for the working class and various forms of social dysfunction.
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