Case studies of large-scale agricultural investment in Paraguay, Guatemala and Colombia show how monoculture expansion is displacing communities, undermining smallholder livelihoods and worsening local food security. Even when companies say they operate responsibly, their business model determines who bears the risks, who has access to capital and where market power lies. Responsibility should mean benefits and costs are fairly distributed and all rights upheld, including land rights. Private agricultural investment is needed, but it should complement rather than undermine smallholders, who are the main investors in agriculture.An adapted version of this paper appeared in the June 2014 issue of the peer-reviewed journal Food Chain, Volume 4 Number 2. See the developmentbookshelf.com web site at http://developmentbookshelf.com/link.asp?id=L903X8202076.See alsoThe Soy Mirage: The limits of corporate social responsibilityDivide and Purchase: How land ownership is being concentrated in Colombi