What are the causes of economic disparities or representational disparities between and among racial and ethnic groups in society?

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  1. What are the causes of economic disparities or representational disparities between and among racial and ethnic groups in society?
  2. Is it only because of negative discrimination (based on race/ethnicity)?
  3. What are the other relevant factors discussed by Thomas Sowell and/or Walter Williams?
  4. What, if anything, should our American federal or state governments do about economic disparities or representational disparities between and among racial groups in society? Why?