Two discrete, sociological theories explain and justify gentrification as an economic process ( production-side theory ) and as a social process ( consumption-side theory ) that occurs when the suburban gentry tire of the automobile-dependent urban sprawl style of life ; thus, professionals, empty nest aged parents, and recent university graduates perceive the attractiveness of the city center — earlier abandoned during white flight — especially if the poor community possesses a transport hub and its architecture sustains the pedestrian traffic that allows the proper human relations impeded by ( sub ) urban sprawl.

In the 20th century the trend toward abstraction coincided with advances in science, technology, and changes in urban life, eventually reflecting an interest in psychoanalytic theory.

Adopting Thomas Malthus's population theory, they saw poor urban conditions as inevitable, as they believed population growth would outstrip food production ; and they considered that to be desirable, as starvation would help limit population growth.

* Allen J. Scott ( born 1938 ), winner of Vautrin Lud Prize in 2003 and the Anders Retzius Gold medal 2009 ; author of numerous books and papers on economic and urban geography, known for his work on regional development, new industrial spaces, agglomeration theory, global city-regions and the cultural economy.

* Kosher tax, an urban legend and antisemitic conspiracy theory

Thus, its functions largely overreached simple law enforcement activities and included public health concerns, urban planning ( which was important because of the miasma theory of disease ; thus, cemeteries were moved out of town, etc.

The idea of a South American – styled urban guerrilla movement, similar to the Tupamaros movement in Uruguay, combined with Régis Debray's theory of urban warfare and ideas drawn from Maoism, appealed to a number of people, including Patricia Michelle Soltysik ( a. k. a. " Mizmoon ").

Smart growth is an urban planning and transportation theory that concentrates growth in compact walkable urban centers to avoid sprawl.

Urban design demands a good understanding of a wide range of subjects from physical geography, through to social science, and an appreciation for disciplines, such as real estate development, urban economics, political economy and social theory.

Some aspects of privately owned spaces, such as building facades or domestic gardens, also contribute to public space and are therefore also considered by urban design theory.

Important writers on urban design theory include Christopher Alexander, Peter Calthorpe, Gordon Cullen, Andres Duany, Jane Jacobs, Mitchell Joachim, Jan Gehl, Allan B. Jacobs, Kevin Lynch, Aldo Rossi, Colin Rowe, Robert Venturi, William H. Whyte, Bill Hillier, and Elizabeth Plater-Zyberk.

Many architecture, landscape and planning programs incorporate urban design theory and design subjects into their curricula and there are an increasing number of university programs offering degrees in urban design, usually at post-graduate level.

Kevin Lynch's The Image of the City of 1961 was also seminal to the movement, particularly with regards to the concept of legibility, and the reduction of urban design theory to five basic elements-paths, districts, edges, nodes, landmarks.

Topics in regional science include, but are not limited to location theory or spatial economics, location modeling, transportation, migration analysis, land use and urban development, interindustry analysis, environmental and ecological analysis, resource management, urban and regional policy analysis, geographical information systems, and spatial data analysis.

Faculty also taught courses in mathematical programming, transportation economics, labor economics, energy and ecological policy modeling, spatial statistics, spatial interaction theory and models, benefit / cost analysis, urban and regional analysis, and economic development theory, among others.

The first theory, demographic-ecological, attempts to explain gentrification through the analysis of demographics: population, social organization, environment, and technology.

The second theory proposed by London and Palen is based on a sociocultural explanation of gentrification.

According to Bruce D. Johnson, Andrew Golub, and James McCabe, the application of the broken windows theory in policing and policy-making can result in development projects that decrease physical disorder but promote undesired gentrification.

Given the variety of approaches, Economic Geography has taken to many different subject matters, including: the location of industries, economies of agglomeration ( also known as " linkages "), transportation, international trade, economic development, real estate, gentrification, ethnic economies, gendered economies, core-periphery theory, the economics of urban form, the relationship between the environment and the economy ( tying into a long history of geographers studying culture-environment interaction ), and globalization.

Peter Leeson argues that " the case for anarchy derives its strength from empirical evidence, not theory.

Moreover, there is the 1908 theory that America derives from Richard Amerike of Bristol, England, financier of John Cabot's 1497 expedition.

Natural-law theory therefore distinguishes between " criminality " ( which derives from human nature ) and " illegality " ( which originates with the interests of those in power ).

One theory is that it originally derives from the Latin word macula, meaning " spot " or “ opacity ” ( as in macula of retina ).

This version of " critical " theory derives from Kant's ( 18th-century ) and Marx's ( 19th Century ) use of the term " critique ", as in Kant's Critique of Pure Reason and Marx's concept that his work Das Kapital ( Capital ) forms a " critique of political economy.

This version of " critical " theory derives from the notion of literary criticism as establishing and enhancing the understanding and evaluation of literature in the search for truth.

Another theory holds that edda derives from Old Norse óðr, " poetry.

Harkins believes the most credible theory of the term's origin is that it derives from the linkage of two older Scottish expressions, " hill-folk " and " billie " which was a synonym for " fellow ", similar to " guy " or " bloke ".

For advocates of the theory that justice is part of natural law ( e. g., John Locke ), it involves the system of consequences that naturally derives from any action or choice.

An alternative theory, which has gained only limited acceptance among professional scholars, derives the name Arthur from Arcturus, the brightest star in the constellation Boötes, near Ursa Major or the Great Bear.

However, the theory has been traced back to Treatise of Taxes, written in 1662 by Sir William Petty and to John Locke's notion, set out in the Second Treatise on Government ( 1689 ), that property derives from labor through the act of " mixing " one's labor with items in the common store of goods, though this has alternatively been seen as a labor theory of property.

The phrase " the Old Religion ," used by Wiccans and Neopagans to describe an ancestral pagan religion, derives from Murrayite theory.

The modern theory of natural selection derives from the work of Charles Darwin in the nineteenth century.

The name photon derives from the Greek word for light, ( transliterated phôs ), and was coined in 1926 by the physical chemist Gilbert Lewis, who published a speculative theory in which photons were " uncreatable and indestructible ".

Another theory, proposed by Jacobsohn and supported by others, is that the name derives from the attested Illyrian locality Palaeste, whose inhabitants would have been called Palaestīnī according to normal grammatical practice.

" A further theory is that it derives from Johnson's word skavoovie, with which he was known to greet his friends.

According to one theory, the name derives from the fortified dessert wine, sherry ( which is sometimes sweetened after fermentation ) that, in England, once bore the nickname " sack ").

A fourth theory is that the word derives from 撈麵 ( lāomiàn, " lo mein "), which in Cantonese 撈 means to " stir ", and the name refers to the method of preparation by stirring the noodles with a sauce.

* The most accepted theory on the origin of the name Vardar derives Bardários from Thracian, from PIE *( s ) wordo-wori-' black water ' ( cf.

One theory is that it derives from the Yucatec Maya word xok, pronounced ' shok '.

( Another theory derives the first element from OHG win ' meadow, pasture.

A common theory is that it derives from a West Slavonic name meaning " beneath the oaks ", i. e., the corrupted " pod dubmi / dubimi " (' pod '=" beneath, ' dub '=" oak ").

Another theory is that " Cherokee " derives from a Lower Creek word, Ciló-kki, meaning someone who speaks another language.