Harris's 1978 book Capital Accumulation and Income Distribution critiques mainstream economic theories, using mathematical modeling to propose an alternative model for thinking about the effects of capital accumulation on income inequality, economic growth, instability, and other phenomena. He has worked extensively on analysis and policy regarding the economy of Jamaica.
He served in Jamaica, at various times, as economic policy consultant to the government and as economic adviser to successive prime ministers.
In 2021, he was awarded Jamaica's Order of Merit, the country's third-highest national honor, for his "contribution to national development"