If you trim the two outliers on the top right plot, it becomes a spherical blob: http://i2.wp.com/microeconomicinsights.org/wp-content/uploads/2017/11/image001.

If you trim the two outliers on the top right plot, it becomes a spherical blob: http://i2.wp.com/microeconomicinsights.org/wp-content/uploads/2017/11/image001.png http://i2.wp.com/microeconomicinsights.org/wp-content/upload... microeconomics.org is owned by the "Institute for Fiscal Studies," a British think-tank whose funders I haven't bothered to find. If you find the funders, I suspect you can predict the red lines.