There are however several unique challenges that need to be considered in order to see this potential maximized. Because the poor will often own smaller amounts of land, ensuring their participation will require setting the minimize land size requirements for the programme adequately low. While the inclusion of a larger number of smaller plots will tend to increase transaction costs, as outlined previously, a number of technical and institutional innovations can be employed to limit these effects. Ensuring the ability of the poor to participate will also includes ensuring that they have adequate access to the necessary capital, insurance and other financial services. As PES programmes often include upfront costs and can involve considerable investment risk, these services are critical to ensuring programme accessibility. Furthermore, because the poor are often renters of land rather than the owners of it, PES also has the potential to adversely affect the livelihoods of the poor by increasing the opportunity cost of the land to land owners and therefore increase the rent demanded.