How much does education matter?

Greg Mankiw thinks that correlating SATS scores and subsequent earned income misses the point that inherited intelligence are a factor in both. This appears to be supported by the graph in Alex Tabarrok's blog that shows "higher parental income predicts higher child income but only for biological children and not for adoptees."

David Davis points out that the £45,000 true cost of a university education is not always recouped by graduate earnings. (See also Charles Hugh Smith's piece, "Is Higher Education Worth a Lifetime of Debt?")

I have read that there is a positive correlation between shoe size and IQ. Public policy is to buy big shoes for everybody so they get smarter.

Speaker or silencer?

I now read in The Grumbler that David Davis was prevented by the Speaker of the House of Commons from delivering his resignation speech to the House, and had to go outside the building to say it to journalists instead. Words fail.

Is it OK to have principles?

Shadow Home Secretary David Davis resigns his Parliamentary seat to fight a by-election on the issue of civil liberty in Britain, and Michael White in the Guardian plays the sneering curmudgeon; parti pris?

UPDATE

Someone put the text of Mr Davis' speech as a comment to Michael White's piece. Here are a couple of extracts:

This Counter Terrorism Bill will in all likelihood be rejected by the House of Lords... But because the impetus behind it is political, the government will be tempted to use the Parliament Act...
It has no democratic mandate to do this...

... I am just a piece in this chess game.

Folly? Vanity? My eye (and Betty Martin).