The avocado you picked up at the grocery store almost certainly started its journey at a family farm in Mexico. From there, a packing company bought, sorted, and shipped it to the United States. Stateside, a distributor bought it and shipped it to the grocery store in your town. By the time you paid a dollar for that avocado, it had passed through the hands of perhaps four companies, each competing with several others for a slice of the fruit trade. That single dollar covered all the costs: growing, packing, shipping, displaying, and ringing it up at the checkout stand....