Migration in Modern World History, 1500-2000 (Wadsworth, 2000), an interactive CD-ROM, resulted from years of collaborative work at the World History Center.

My global overview of migration over the full span of human history, Migration in World History (Routledge, 2004), has been influential in encouraging collaborative and interdisciplinary study of migration. I participated in a December 2005 conference at the Netherlands Institute for Advanced Study, Wassenaar, that will lead to a volume on interdisciplinary methods in migration history, edited by Leo Lucassen, Jan Lucassen, and myself.

My simulation of migration - for Atlantic slave trade, Old World slave trade, and voluntary European migration - is now available online as the Migration Simulation

In addition, my 2006 article interpreting early human migration, "Homo sapiens Populates the Earth: A provisional synthesis, privileging linguistic evidence" is available online in the Journal of World History. A companion study on "Patterns of Human Migration" is forthcoming in Social Evolution in History.