In addition to prohibiting development, reserving land for open space converts a private good (use of the land for commercial development purposes) into a public good (open access to the land for general public enjoyment). One way a society can reserve land for open space for the benefit of all is through zoning - prohibiting development in certain areas. As an alternative, a government may establish a budget category, funded by tax collections, for purchasing lands for public use. Is one approach more likely than the other to lead to a social optimum (i.e., be most consistent with consumer preferences for public and private goods)? What factors or conditions might favor one approach over another?