Alex Tabarrok is a professor of economics at George Mason University. Some of his work is referenced on the website:

• He was a co-initiator of the Open Letter on Immigration addressed to the United States president, mentioned on the economist consensus page.
• His articles, Why Ruin the World’s Best Anti-Poverty Program?, and Economic and Moral Factors in Favor of Open Immigration.

Relevant blog posts by Tabarrok:

• Open Borders Day! at Marginal Revolution, March 16, 2014, on the occasion of Open Borders Day.
• The Moral Is the Practical at Marginal Revolution, February 15, 2014, cited at moral versus practical arguments.