“…14 In addition to such standard gravity variables, immigration policy variables in the destination country have been found to have a significant effect (Bertocchi and Strozzi, 2008;Mayda, 2010;Letouzé et al, 2009;Ortega and Peri, 2009). We note, for later reference, that a small number of papers introduce some trade variable into the migration gravity model (Molle and Van Mourik, 1988;Gallardo-Sejas et al, 2006;Letouzé et al, 2009). In all cases, the trade variable is positive and, usually, significant.…”