We began this book by examining land-based natural resources, because establishing clearly specified rights is easier when the resource is im-mobile. For food, timber, and even recreational amenities, markets can allocate resources when the rights to the land are private. When production focuses on minerals below the surface or wildlife on the surface, defining and enforcing property rights does become more costly. As the value of these resources rises, however, it also becomes more worthwhile to invest in defining and enforcing property rights to them. When legal institutions encourage rather than raise the cost of establishing private property rights, markets can evolve for recreational and environmental amenities as well as for traditional products.