As a Realtor, I am bound by a code of ethics. While it is a lengthy document, I really like the first paragraph:
The Preamble to the Code of Ethics
Under all is the land. Upon its wise utilization and widely allocated ownership depend the survival and growth of free institutions and of our civilization. REALTORS ® should recognize that the interests of the nation and its citizens require the highest and best use of the land and the widest distribution of land ownership. They require the creation of adequate housing, the building of functioning cities, the development of productive industries and farms, and the preservation of a healthful environment.