American hedge funds are buying massive amounts of land–larger in size than the state of California–in Africa, often without proper contracts, according to the Oakland Institute, an independent policy think tank. The hedge funds say that it’s an effort to uplift the economies of African nations, but some critics say it’s a “land grab;” an opportunity to buy cheap land to grow food crops that will be exported to richer countries, ultimately  depleting  Africa’s natural resources and raising global food prices.   Mark Doyle, International Development Correspondent for our partner, the BBC, speaks with us about this from London.