and urbanization that seek to define and measure progress on whether different countries or cultures agree to accept industrial technologies in their eco-systems. Other approaches, like those that start from international treaties on cultural rights of indigenous peoples to maintain traditional cultures, measure the ability of those cultures to maintain their traditions within their eco-systems at whatever level of productivity they choose. The Lempert-Nguyen indicator, devised in 2008 for practitioners, starts with the standards for sustainable development that have been agreed upon by the international community and then looks at whether intergovernmental organizations such as the UNDP and other development actors are applying these principles in their projects and work as a whole. In using sustainability indicators, it is important to distinguish between three types of sustainability that are often mentioned in international development: Sustainability of a culture (human system) within its resources and environment; Sustainability of a specific stream of benefits or productivity (usually just an economic measure); and Sustainability of a particular institution or project without additional assistance (institutionalization of an input). The following list is not exhaustive but contains the major points of view: "Daly Rules" approach University of Maryland School of Public Policy professor and former Chief Economist for the World Bank Herman E. Daly (working from theory initially developed by Romanian economist Nicholas Georgescu-Roegen and laid out in his 1971 opus "The Entropy Law and the Economic Process") suggests the following three operational rules defining the condition of ecological (thermodynamic) sustainability: Renewable resources such as fish, soil, and groundwater must be used no faster than the rate at which they regenerate. Nonrenewable resources such as minerals and fossil fuels must be used no faster than renewable substitutes for them can be put into place. Pollution and wastes must be emitted no faster than natural systems can absorb them, recycle them, or render them harmless. Some commentators have argued that the "Daly Rules", being based on ecological theory and the Laws of Thermodynamics, should perhaps be considered implicit or foundational for the many other systems that are advocated, and are thus the most straightforward system for operationalization of the Bruntland Definition. In this view, the Bruntland Definition and the Daly Rules can be seen as complementary—Bruntland provides the ethical goal of non-depletion of natural capital, Daly details parsimoniously how this ethic is operationalized in physical terms. The system is rationally complete, and in agreement with physical