Markets: The New Segregation" which termed smart growth "restricted growth" and suggested that smart growth policies disfavor minorities and the poor by driving up housing prices. Some libertarian groups, such as the Cato Institute, criticize smart growth on the grounds that it leads to greatly increased land values, and people with average incomes can no longer afford to buy detached houses. A number of ecological economists claim that industrial civilization has already "overshot" the carrying capacity of the Earth, and "smart growth" is mostly an illusion. Instead, a steady state economy would be needed to bring human societies back into a necessary balance with the ability of the ecosystem to sustain humans (and other species). A study released in November 2009 characterized the smart-growth policies in the U.S. state of Maryland as a failure, concluding that "[t]here is no evidence after ten years that [smart-growth laws] have had any effect on development patterns." Factors include a lack of incentives for builders to redevelop older neighborhoods and limits on the ability of state planners to force local jurisdictions to approve high-density developments in "smart-growth" areas. Buyers demand low-density development and voters tend to oppose high density developments near them. Beginning in 2010, groups generally associated with the Tea Party movement began to identify Smart Growth as an outgrowth of the United Nations Agenda 21 which they viewed as an attempt by international interests to force a "sustainable" lifestyle on the United States. However planning groups and even some smart growth opponents counter that Smart Growth concepts and groups predate the 1992 Agenda 21 conference. In addition the word "sustainable development" as used in the Agenda 21 report is often misread to mean real estate development when it typically refers to the much broader concept of human development in the United Nations and foreign aid context which addresses a broader slate of economic, health, poverty, and education issues. See also Related topics New Urbanism Community Preservation Act Garden city movement Planned community Principles of Intelligent Urbanism Slow architecture Sustainable city Traditional Neighborhood Development (TND) Urban renewal Urban vitality Agenda 21 Soft law Sustainable development Organizations Futurewise.org Smart Growth America Greenbelt Alliance HUD USER Regulatory Barriers Clearinghouse PolicyLink References Further reading "Urban Alchemy" — about the need for efficient transit to serve smart growth "Smart Growth: A Critical Review of the State of the Art" — by Aseem Inam, chapter in book, Companion