Economic growth is the casualty of a widening gap between the rich and the poor among member countries of the Paris-based Organisation for Economic Co-operation and Development (OECD), according to a report issued last month. The richest 10% of the population in OECD countries earn 9.5 times more than the poorest 10%. In the 1980s, that ratio was 7:1, and the income gap is at its highest level in about 30 years. The report suggests that the growing income inequality has, over the past two decades, cost the U.S. between 6 and 7 percentage points in economic growth, nine points in the U.K., and 10 points in New Zealand and Mexico. “Income inequality is a source of concern not just from a social point of view, but also from an economic point of view,” said Stefano Scarpetta, director of employment, labor and social affairs at the OECD. He attributed the growing inequality to globalization and technological progress, and called for more access to quality education for people in lower-income households.…