Unintentional introductions of nonindigenous plants, animals, and microbes cause significant ecological and agricultural crop damage worldwide. Trade in both manufactured and agricultural goods is a primary vector for such introductions. Fusing simple models of trade and biological...

After decades of stability, the technologies used by workers to locate new jobs began to change rapidly with the diffusion of internet access in the late 1990's. Which types of persons incorporated the internet into their job search strategy, and did searching for work on line help these workers...