Analysts of the food system use a figure called CR4, which stands for the concentration ratio of the top four companies in a particular sector. For example, more than 83% of the market in beef packing is controlled by the top four beef packers, which as of 2007 are Tyson, Cargill, Swift & Co., and National Beef Packing Co. So we can say that in beef packing, the CR4=83%.
Phil Howard, a sociology professor at Michigan State University, made this graphic to represent the level of concentration in a number of different sectors of the agri-food system.
Notice that the colors represent particular companies. What do you think it means that some companies are in the top four of multiple sectors? How do you think that affects farmers? How do you think it affects you?
Check out Phil Howard's website for more awesome infographics about food and agriculture.