Editing Slum (section)

==Causes that create and expand slums==
Slums sprout and continue for a combination of demographic, social, economic, and political reasons. Common causes include rapid rural-to-urban migration, poor planning, economic stagnation and depression, poverty, high unemployment, informal economy, colonialism and segregation, politics, natural disasters and social conflicts.

===Rural–urban migration===
[[File:kibera.jpg|thumb|[[Kibera]] slum in [[Nairobi]], Kenya, the second-largest slum in Africa<ref name="imcworldwide">{{cite web |url=http://www.imcworldwide.org/content/article/detail/766/ |title=International Medical Corps – International Medical Corps |access-date=July 23, 2015 |url-status=dead |archive-url=https://web.archive.org/web/20110728132453/http://www.imcworldwide.org/content/article/detail/766/ |archive-date=July 28, 2011}}</ref><ref>{{Cite web |url=http://www.unhabitat.org/content.asp?typeid=19&catid=548&cid=4962 |title=Participating countries |access-date=2009-01-21 |archive-url=https://web.archive.org/web/20090114031916/http://www.unhabitat.org/content.asp?typeid=19&catid=548&cid=4962 |archive-date=2009-01-14 |url-status=live}}</ref><ref>[http://www.dominionpaper.ca/articles/1703 "Machetes, Ethnic Conflict and Reductionism"] {{Webarchive|url=https://web.archive.org/web/20080519150442/http://www.dominionpaper.ca/articles/1703 |date=2008-05-19}} ''[[The Dominion (Canada)|The Dominion]]''</ref> and third-largest in the world.<ref name="imcworldwide" />]]

Rural–urban migration is one of the causes attributed to the formation and expansion of slums.<ref name="whyslums" /> Since 1950, world population has increased at a far greater rate than the total amount of arable land, even as [[agriculture]] contributes a much smaller percentage of the total economy. For example, in India, agriculture accounted for 52% of its GDP in 1954 and only 19% in 2004;<ref>{{Cite web |url=http://planningcommission.nic.in/data/datatable/2504/databook_%2029.pdf |title=Gross Domestic Product (GDP) from Agriculture and Allied Sector and its Percentage Share to Total GDP (1954-55 to 2012-13) |access-date=2013-09-16 |archive-url=https://web.archive.org/web/20131024061050/http://planningcommission.nic.in/data/datatable/2504/databook_%2029.pdf |archive-date=2013-10-24 |url-status=dead}}</ref> in Brazil, the 2050 GDP contribution of agriculture is one-fifth of its contribution in 1951.<ref>[http://www.brookings.edu/~/media/research/files/papers/2008/5/brazil%20agriculture%20barros/05_brazil_agriculture_barros.pdf Brazil: The Challenges in Becoming an Agricultural Superpower] {{Webarchive|url=https://web.archive.org/web/20131023053833/http://www.brookings.edu/~/media/research/files/papers/2008/5/brazil%20agriculture%20barros/05_brazil_agriculture_barros.pdf |date=2013-10-23}} Geraldo Barros, Brookings Institution (2008)</ref> Agriculture, meanwhile, has also become higher yielding, less disease prone, less physically harsh and more efficient with tractors and other equipment. The proportion of people working in agriculture has declined by 30% over the last 50 years, while global population has increased by 250%.<ref name="whyslums" />

Many people move to [[urban areas]] primarily because cities promise more jobs, better schools for poor's children, and diverse income opportunities than subsistence farming in [[rural areas]].<ref>Judy Baker (2008). [https://archive.today/20130916233437/http://go.worldbank.org/KT759KE9S0 "Urban Poverty – An Overview"]. The World Bank.</ref> For example, in 1995, 95.8% of migrants to [[Surabaya]], Indonesia reported that jobs were their primary motivation for moving to the city.<ref>Tjiptoherijanto, Prinjono, and Eddy Hasmi. "Urbanization and Urban Growth in Indonesia". ''Asian Urbanization in the New Millennium''. Ed. Gayl D. Ness and Prem P. Talwar. Singapore: Marshall Cavendish Academic, 2005., page 162</ref> However, some rural migrants may not find jobs immediately because of their lack of skills and the increasingly competitive job markets, which leads to their financial shortage.<ref name="Todaro">{{cite journal |last=Todaro |first=Michael P. |title=A Model of Labour Migration and Urban Unemployment in Less Developed Countries |journal=The American Economic Review |year=1969 |volume=59 |issue=1 |pages=138–148}}</ref> Many cities, on the other hand, do not provide enough low-cost [[housing]] for a large number of rural-urban migrant workers. Some rural–urban [[migrant workers]] cannot afford housing in cities and eventually settle down in only affordable slums.<ref name="Craster">{{cite journal |last=Craster |first=Charles V |title=Slum Clearance: The Newark Plan |journal=American Journal of Public Health and the Nation's Health |year=1944 |volume=34 |issue=9 |pages=935–940 |doi=10.2105/ajph.34.9.935 |pmid=18016046 |pmc=1625197}}</ref> Further, rural migrants, mainly lured by higher incomes, continue to flood into cities. They thus expand the existing urban slums.<ref name="Todaro" />

According to Ali and Toran, [[social networks]] might also explain rural–urban migration and people's ultimate settlement in slums. In addition to migration for jobs, a portion of people migrate to cities because of their connection with relatives or families. Once their family support in urban areas is in slums, those rural migrants intend to live with them in slums<ref>{{cite journal |last=Ali |first=Mohammed Akhter |author2=Kavita Toran |title=Migration, Slums and Urban Squalor – A case study of Gandhinagar Slum |journal=Proceedings of the Third International Conference on Environment and Health |year=2004 |pages=1–10}}</ref>

===Urbanization===
[[File:Rocinha Favela Brazil Slums.jpg|thumb|A slum in [[Rio de Janeiro]], Brazil. Rocinha favela is next to skyscrapers and wealthier parts of the city, a location that provides jobs and easy commute to those who live in the slums.]]
The formation of slums is closely linked to [[urbanization]].<ref name="Davis">{{cite book |last=Davis |first=Mike |title=Planet of Slums |year=2006 |publisher=Verso}}</ref>{{page needed|date=October 2024}} In 2008, more than 50% of the world's population lived in urban areas. In China, for example, it is estimated that the population living in urban areas will increase by 10% within a decade according to its current rates of urbanization.<ref>{{cite book |title=State of the world population 2007: unleashing the potential of urban growth |year=2007 |publisher=United Nations Population Fund |location=New York}}</ref>{{page needed|date=October 2024}} The UN-Habitat reports that 43% of urban population in [[developing countries]] and 78% of those in the least developed countries are slum dwellers.<ref name="grhs2003" />

Some scholars suggest that urbanization creates slums because local governments are unable to manage urbanization, and [[migrant workers]] without an affordable place to live in, dwell in slums.<ref name="Hammel 1964 346–358">{{cite journal |last=Hammel |first=Eugene A. |title=Some characteristics of rural village and urban slum populations on the coast of Peru |journal=Southwestern Journal of Anthropology |volume=20 |issue=4 |year=1964 |pages=346–358 |doi=10.1086/soutjanth.20.4.3629175 |s2cid=130682432}}</ref> Rapid urbanization drives economic growth and causes people to seek working and investment opportunities in urban areas.<ref name="Burke">{{cite journal |last=Patel |first=Ronak B. |author2=Thomas F. Burke |title=Urbanization—an emerging humanitarian disaster|journal=New England Journal of Medicine |year=2009 |volume=361 |issue=8 |pages=741–743 |doi=10.1056/nejmp0810878 |pmid=19692687 |s2cid=19545185 |doi-access=free}}</ref><ref name="Bolay">{{cite journal |last=Bolay |first=Jean-Claude |title=Slums and urban development: questions on society and globalisation |journal=The European Journal of Development Research |year=2006 |volume=18 |issue=2 |pages=284–298 |doi=10.1080/09578810600709492 |citeseerx=10.1.1.464.2718 |s2cid=24793439}}</ref> However, as evidenced by poor urban [[infrastructure]] and insufficient [[housing]], the local [[governments]] sometimes are unable to manage this transition.<ref>{{cite journal |last=Firdaus |first=Ghuncha |title=Urbanization, emerging slums and increasing health problems: a challenge before the nation: an empirical study with reference to state of uttar pradesh in India |journal=Journal of Environmental Research and Management |year=2012 |volume=3 |issue=9 |pages=146–152}}</ref><ref name="Clonts">{{cite journal |last=Clonts |first=Howard A. |title=Influence of urbanization on land values at the urban periphery |journal=Land Economics |year=1970 |volume=46 |issue=4 |pages=489–497 |doi=10.2307/3145522 |jstor=3145522}}</ref> This incapacity can be attributed to insufficient funds and inexperience to handle and organize problems brought by migration and urbanization.<ref name="Bolay" /> In some cases, local governments ignore the flux of immigrants during the process of urbanization.<ref name="Burke" /> Such examples can be found in many [[List of sovereign states and dependent territories in Africa|African]] countries. In the early 1950s, many African governments believed that slums would finally disappear with economic growth in urban areas. They neglected rapidly spreading slums due to increased rural-urban migration caused by urbanization.<ref>{{cite book |title=UN-Habitat (2003b) The Challenge of Slums: Global Report on Human Settlements |year=2003 |publisher=UN-Habitat |location=Earthscan, London}}</ref>{{page needed|date=October 2024}} Some governments, moreover, mapped the land where slums occupied as undeveloped land.<ref>{{cite journal |last=Wekwete |first=K. H |title=Urban management: The recent experience, in Rakodi, C. |journal=The Urban Challenge in Africa |year=2001}}</ref>

Another type of urbanization does not involve economic growth but [[economic stagnation]] or low growth, mainly contributing to slum growth in [[Sub-Saharan Africa]] and parts of [[Asia]]. This type of urbanization involves a high rate of [[unemployment]], insufficient financial resources and inconsistent [[urban planning]] policy.<ref>{{cite book |last=Cheru |first=F |title=Globalization and uneven development in Africa: The limits to effective urban governance in the provision of basic services |year=2005 |publisher=UCLA Globalization Research Center-Africa}}</ref>{{page needed|date=October 2024}} In these areas, an increase of 1% in urban population will result in an increase of 1.84% in slum prevalence.<ref name="barimslum" />

Urbanization might also force some people to live in slums when it influences [[land use]] by transforming agricultural land into urban areas and increases land value. During the process of urbanization, some agricultural land is used for additional urban activities. More investment will come into these areas, which increases the land value.<ref>{{cite journal |last=Rancich |first=Michael T. |title=Land value changes in an area undergoing urbanization |journal=Land Economics |year=1970 |volume=46 |issue=1 |pages=32–40 |doi=10.2307/3145421 |jstor=3145421}}</ref> Before some land is completely urbanized, there is a period when the land can be used for neither urban activities nor agriculture. The income from the land will decline, which decreases the people's incomes in that area. The gap between people's low income and the high land price forces some people to look for and construct cheap [[informal settlements]], which are known as slums in urban areas.<ref name="Clonts" /> The transformation of agricultural land also provides [[surplus labour]], as peasants have to seek jobs in urban areas as rural-urban [[migrant workers]].<ref name="Hammel 1964 346–358" />

Many slums are part of [[economies of agglomeration]] in which there is an emergence of [[economies of scale]] at the firm level, transport costs and the mobility of the industrial labour force.<ref name="Alonso" /> The increase in returns of scale will mean that the production of each good will take place in a single location.<ref name="Alonso">{{cite journal |last1=Alonso-Villar |first1=Olga |title=Large Metropolises in the Third World: An Explanation. |journal=Urban Studies |date=2001 |volume=38 |issue=8 |page=1368 |doi=10.1080/00420980120061070 |bibcode=2001UrbSt..38.1359A |s2cid=153400618}}</ref> And even though an agglomerated economy benefits these cities by bringing in specialization and multiple competing suppliers, the conditions of slums continue to lag behind in terms of quality and adequate housing. Alonso-Villar argues that the existence of transport costs implies that the best locations for a firm will be those with easy access to markets, and the best locations for workers, those with easy access to goods. The concentration is the result of a self-reinforcing process of agglomeration.<ref name="Alonso" /> Concentration is a common trend of the distribution of population. Urban growth is dramatically intense in the less developed countries, where a large number of huge cities have started to appear; which means high poverty rates, crime, pollution and congestion.<ref name="Alonso" />

=== Poor house planning ===
[[File:Slums and Skyscrapers in La Paz.jpg|thumb|right|A large slum pictured behind skyscrapers in a more developed area in [[La Paz]], Bolivia.]]
Lack of affordable low-cost housing and poor planning encourages the supply side of slums.<ref name="lse">[http://lsecities.net/media/objects/articles/istanbuls-gecekondus Istanbul's Gecekondus] {{Webarchive|url=https://web.archive.org/web/20131022184541/http://lsecities.net/media/objects/articles/istanbuls-gecekondus |date=2013-10-22}} Orhan Esen, London School of Economics and Political Science (2009)</ref> The Millennium Development Goals proposes that member nations should make a "significant improvement in the lives of at least 100 million slum dwellers" by 2020.<ref>{{cite journal |last=United Nations |title=United Nations Millennium Declaration |journal=United Nations Millennium Summit |year=2000 |url=https://www.un.org/millennium/declaration/ares552e.pdf |access-date=2017-06-29 |archive-url=https://web.archive.org/web/20180307225929/http://www.un.org/millennium/declaration/ares552e.pdf |archive-date=2018-03-07 |url-status=live}}</ref> If member nations succeed in achieving this goal, 90% of the world total slum dwellers may remain in the poorly housed settlements by 2020.<ref name="Choguill">{{cite journal |last=Choguill |first=Charles L. |title=The search for policies to support sustainable housing |journal=Habitat International |year=2007 |volume=31 |issue=1 |pages=143–149 |doi=10.1016/j.habitatint.2006.12.001}}</ref> Choguill claims that the large number of slum dwellers indicates a deficiency of practical housing policy.<ref name="Choguill" /> Whenever there is a significant gap in growing demand for housing and insufficient supply of affordable housing, this gap is typically met in part by slums.<ref name="lse" /> ''The Economist'' has observed that "good housing is obviously better than a slum, but a slum is better than none".<ref>[http://www.economist.com/node/21558572 Scourge of slums] {{Webarchive|url=https://web.archive.org/web/20130927000839/http://www.economist.com/node/21558572 |date=2013-09-27}} ''The Economist'' (July 14, 2012)</ref>

Insufficient [[financial]] resources <ref name="Walther">{{cite journal |last=Walther |first=James V. |title=Cause or Effect of Slums? |journal=Challenge |year=1965 |volume=13 |issue=14 |pages=24–25 |doi=10.1080/05775132.1965.11469790}}</ref> and lack of coordination in government bureaucracy <ref name="barimslum" /> are two main causes of poor house planning. Financial deficiency in some governments may explain the lack of affordable [[public housing]] for the poor since any improvement of the tenant in slums and expansion of [[public housing]] programs involve a great increase in the government expenditure.<ref name="Walther" /> The problem can also lie on the failure in coordination among different departments in charge of economic development, [[urban planning]], and land allocation. In some cities, governments assume that the housing [[Market (economics)|market]] will adjust the supply of housing with a change in demand. However, with little economic incentive, the housing market is more likely to develop middle-income housing rather than low-cost housing. The urban poor gradually become marginalized in the housing market where few houses are built to sell to them.<ref name="barimslum" /><ref>{{cite journal |last=Ooi |first=Giok Ling |author2=Kai Hong Phua |title=Urbanization and slum formation |journal=Journal of Urban Health |volume=84 |issue=1 |pages=27–34 |pmid=17387618 |year=2007 |doi=10.1007/s11524-007-9167-5 |pmc=1891640}}</ref>

===Colonialism and segregation===
[[File:Pottery unit in Dharavi, Mumbai.jpg|thumb|An integrated slum dwelling and informal economy inside Dharavi of [[Mumbai]]. Dharavi slum started in 1887 with industrial and segregationist policies of the British colonial era. The slum housing, tanneries, pottery and other economy established inside and around Dharavi during the British rule of India.<ref name="jn2010" /><ref>Sharma, K. (2000). ''Rediscovering Dharavi: stories from Asia's largest slum''. Penguin, {{ISBN|978-0141000237}}, pages 3–11</ref><ref>Pacione, Michael (2006), Mumbai, Cities, 23(3), pages 229–238</ref>]]

Some of the slums in today's world are a product of [[urbanization]] brought by [[colonialism]]. For instance, the [[Europeans]] arrived in [[Kenya]] in the nineteenth century and created urban centers such as [[Nairobi]] mainly to serve their financial interests. They regarded the Africans as temporary migrants and needed them only for supply of [[Employment|labour]]. The housing policy aiming to accommodate these workers was not well enforced and the government built settlements in the form of single-occupancy bedspaces. Due to the cost of time and money in their movement back and forth between rural and urban areas, their families gradually migrated to the urban centre. As they could not afford to buy houses, slums were thus formed.<ref>{{cite journal |last=Obudho |first=R. A. |author2=G. O. Aduwo |title=Slum and squatter settlements in urban centres of Kenya: Towards a planning strategy |journal=Journal of Housing and the Built Environment |year=1989 |volume=4 |issue=1 |pages=17–30 |doi=10.1007/bf02498028 |s2cid=154852140}}</ref>

Others were created because of [[Residential segregation|segregation]] imposed by the colonialists. For example, [[Dharavi|Dharavi slum of Mumbai]] – now one of the largest slums in [[India]], used to be a village referred to as Koliwadas, and Mumbai used to be referred as Bombay. In 1887, the British colonial government expelled all tanneries, other noxious industry and poor natives who worked in the peninsular part of the city and colonial housing area, to what was back then the northern fringe of the city – a settlement now called Dharavi. This settlement attracted no colonial supervision or investment in terms of road infrastructure, [[sanitation]], public services or housing. The poor moved into Dharavi, found work as servants in colonial offices and homes and in the foreign owned tanneries and other polluting industries near Dharavi. To live, the poor built shanty towns within easy commute to work. By 1947, the year India became an independent nation of the commonwealth, Dharavi had blossomed into Bombay's largest slum.<ref name="jn2010">Jan Nijman (February 2010). "A Study of Space in Mumbai's Slums". ''Tijdschrift voor economische en sociale geografie''. Volume 101, Issue 1, pages 4–17.</ref>

Similarly, some of the slums of [[Lagos]], Nigeria sprouted because of neglect and policies of the colonial era.<ref>Liora Bigon, "Between Local and Colonial Perceptions: The History of Slum Clearances in Lagos" (Nigeria), 1924–1960, ''African and Asian Studies'', Volume 7, Number 1, 2008, pages 49–76 (28)</ref> During apartheid era of [[South Africa]], under the pretext of sanitation and plague epidemic prevention, racial and ethnic group segregation was pursued, people of colour were moved to the fringes of the city, policies that created Soweto and other slums – officially called townships.<ref>Beinart, W., & Dubow, S. (Eds.), (2013), ''Segregation and apartheid in twentieth century South Africa'', Routledge, pages 25–35</ref> Large slums started at the fringes of segregation-conscious colonial city centers of Latin America.<ref>Griffin, E., and Ford, L. (1980). "A model of Latin American city structure". ''Geographical Review''. pages 397–422.</ref> Marcuse suggests ghettoes in the United States, and elsewhere, have been created and maintained by the segregationist policies of the state and regionally dominant group.<ref>Marcuse, Peter (2001), [http://www.urbancentre.utoronto.ca/pdfs/curp/Marcuse_Segregationandthe.pdf "Enclaves yes, ghettoes, no: Segregation and the state"] {{Webarchive|url=https://web.archive.org/web/20130921060842/http://www.urbancentre.utoronto.ca/pdfs/curp/Marcuse_Segregationandthe.pdf |date=2013-09-21}}, Lincoln Institute of Land Policy Conference Paper, Columbia University</ref><ref>Bauman, John F (1987). ''Public Housing, Race, and Renewal: Urban Planning in Philadelphia, 1920–1974''. Philadelphia: Temple University Press.</ref>{{page needed|date=October 2024}}

[[File:Makoko auf dem Wasser (5209071096).jpg|thumb|[[Makoko]] – One of the oldest slums in Nigeria, was originally a fishing [[village]] settlement, built on stilts on a lagoon. It developed into a slum and became home to about a hundred thousand people in [[Lagos]]. In 2012, it was partially destroyed by the city government, amidst controversy, to accommodate infrastructure for the city's growing population.<ref>[http://www.economist.com/node/21560615 "Destroying Makoko"] {{Webarchive|url=https://web.archive.org/web/20130904015243/http://www.economist.com/node/21560615 |date=2013-09-04}} ''The Economist'' (August 18, 2012)</ref>]]

===Poor infrastructure, social exclusion and economic stagnation===
[[Social exclusion]] and poor infrastructure forces the poor to adapt to conditions beyond his or her control. Poor families that cannot afford transportation, or those who simply lack any form of affordable public transportation, generally end up in squat settlements within walking distance or close enough to the place of their formal or informal employment.<ref name="lse" /> Ben Arimah cites this social exclusion and poor infrastructure as a cause for numerous slums in African cities.<ref name="barimslum">[http://www.oecd.org/dev/pgd/46837274.pdf "Slums as Expressions of Social Exclusion: Explaining the Prevalence of Slums in African Countries"] {{Webarchive|url=https://web.archive.org/web/20131015175604/http://www.oecd.org/dev/pgd/46837274.pdf |date=2013-10-15}} Ben Arimah, United Nations Human Settlements Programme, Nairobi, Kenya</ref> Poor quality, unpaved streets encourage slums; a 1% increase in paved all-season roads, claims Arimah, reduces slum incidence rate by about 0.35%. Affordable public transport and economic infrastructure empowers poor people to move and consider housing options other than their current slums.<ref>[http://www.irinnews.org/report/84803/africa-improved-infrastructure-key-to-slum-upgrading-un-official "Africa: Improved infrastructure key to slum upgrading – UN Official"] {{Webarchive|url=https://web.archive.org/web/20131021025838/http://www.irinnews.org/report/84803/africa-improved-infrastructure-key-to-slum-upgrading-un-official |date=2013-10-21}} IRIN, United Nations News Service (June 11, 2009)</ref><ref>[http://www.gsd.harvard.edu/academic/fellowships/wheelwright/images/Slum%20Upgrading_Elisa%20Silva.pdf "Latin American Slum Upgrading Efforts"] {{Webarchive|url=https://web.archive.org/web/20131021081502/http://www.gsd.harvard.edu/academic/fellowships/wheelwright/images/Slum%20Upgrading_Elisa%20Silva.pdf |date=2013-10-21}} Elisa Silva, Arthur Wheelwright Traveling Fellowship 2011, Harvard University</ref>

A growing economy that creates jobs at rate faster than population growth, offers people opportunities and incentive to relocate from poor slum to more developed neighborhoods. Economic stagnation, in contrast, creates uncertainties and risks for the poor, encouraging people to stay in the slums. Economic stagnation in a nation with a growing population reduces per capita disposal income in urban and rural areas, increasing urban and rural poverty. Rising rural poverty also encourages migration to urban areas. A poorly performing economy, in other words, increases poverty and rural-to-urban migration, thereby increasing slums.<ref>[http://www.unhabitat.org/pmss/listItemDetails.aspx?publicationID=1156 "The Challenge of Slums: Global Report on Human Settlements" (2003)] {{Webarchive|url=https://web.archive.org/web/20140111041647/http://www.unhabitat.org/pmss/listItemDetails.aspx?publicationID=1156 |date=2014-01-11}}, United Nations Human Settlements Programme; {{ISBN|1-84407-037-9}}</ref><ref name="globalurban.org">[http://www.globalurban.org/GUDMag06Vol2Iss1/Kuiper%20&%20van%20der%20Ree.htm "Growing out of poverty: Urban job Creation and the Millennium Development Goals"] {{Webarchive|url=https://web.archive.org/web/20191031182019/http://www.globalurban.org/GUDMag06Vol2Iss1/Kuiper%20%26%20van%20der%20Ree.htm |date=2019-10-31}} Marja Kuiper and Kees van der Ree, ''Global Urban Development Magazine'', Vol 2, Issue 1, March 2006</ref>

===Informal economy===
Many slums  grow because of growing informal economy which creates demand for workers. Informal economy is that part of an economy that is neither registered as a business nor licensed, one that does not pay taxes and is not monitored by local, state, or federal government.<ref>{{cite web |title=The Informal Economy: Fact Finding Study |url=http://rru.worldbank.org/Documents/PapersLinks/Sida.pdf |publisher=Department for Infrastructure and Economic Cooperation |access-date=November 20, 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111027063706/http://rru.worldbank.org/Documents/PapersLinks/Sida.pdf |archive-date=October 27, 2011}}</ref> Informal economy grows faster than formal economy when government laws and regulations are opaque and excessive, government bureaucracy is corrupt and abusive of entrepreneurs, labour laws are inflexible, or when law enforcement is poor.<ref>Dan Andrews, Aida Caldera Sánchez, and Åsa Johansson (May 30, 2011). [http://www.oecd-ilibrary.org/economics/towards-a-better-understanding-of-the-informal-economy_5kgb1mf88x28-en "Towards a better understanding of informal economy"] {{Webarchive|url=https://web.archive.org/web/20150109045139/http://www.oecd-ilibrary.org/economics/towards-a-better-understanding-of-the-informal-economy_5kgb1mf88x28-en |date=2015-01-09}}. OECD France.</ref> Urban informal sector is between 20 and 60% of most developing economies' GDP; in Kenya, 78 per cent of non-agricultural employment is in the informal sector making up 42 per cent of GDP.<ref name="whyslums" /> In many cities the informal sector accounts for as much as 60 per cent of employment of the urban population. For example, in Benin, slum dwellers comprise 75 per cent of informal sector workers, while in Burkina Faso, the Central African Republic, Chad and Ethiopia, they make up 90 per cent of the informal labour force.<ref>[http://www.unhabitat.org/downloads/docs/3974_95355_A%20Fact%20Sheet%20on%20UN-HABITAT%20and%20Youth%20sr%20Oct%2026.doc "The state of world's cities"] {{Webarchive|url=https://web.archive.org/web/20090704145004/http://www.unhabitat.org/downloads/docs/3974_95355_A%20Fact%20Sheet%20on%20UN-HABITAT%20and%20Youth%20sr%20Oct%2026.doc |date=2009-07-04}} UN Habitat (2007)</ref> Slums thus create an informal alternate economic ecosystem, that demands low paid flexible workers, something impoverished residents of slums deliver. In other words, countries where starting, registering and running a formal business is difficult, tend to encourage informal businesses and slums.<ref>Geoffrey Nwaka (May 2005). [http://www.globalurban.org/Issue1PIMag05/NWAKA%20article.htm "The Urban Informal Sector in Nigeria"] {{Webarchive|url=https://web.archive.org/web/20130913160353/http://www.globalurban.org/Issue1PIMag05/NWAKA%20article.htm |date=2013-09-13}}. ''Global Urban Development Magazine''. Vol 1, No 1.</ref><ref>Sam Sturgis (January 3, 2013). [http://nextcity.org/informalcity/entry/in-nairobis-slums-potential-and-problems-as-big-as-africa-itself "In nairobi's slums, problems and potential as big as Africa itself"] {{Webarchive|url=https://web.archive.org/web/20150109002105/http://nextcity.org/informalcity/entry/in-nairobis-slums-potential-and-problems-as-big-as-africa-itself |date=2015-01-09}}. Rockefeller Foundation.</ref><ref>Jim Yardley (December 28, 2011). [https://www.nytimes.com/2011/12/29/world/asia/in-indian-slum-misery-work-politics-and-hope.html?pagewanted=all&_r=0 "In one slum, misery, work, politics and hope"] {{Webarchive|url=https://web.archive.org/web/20150108233014/http://www.nytimes.com/2011/12/29/world/asia/in-indian-slum-misery-work-politics-and-hope.html?pagewanted=all&_r=0 |date=2015-01-08}} ''The New York Times''.</ref> Without a sustainable formal economy that raise incomes and create opportunities, squalid slums are likely to continue.<ref>Minnery et al., "Slum upgrading and urban governance: Case studies in three South East Asian cities", ''Habitat International'', Volume 39, July 2013, Pages 162–169.</ref>

[[File:Ramos Arizpe slums.jpg|thumb|A slum near [[Ramos Arizpe]] in [[Mexico]].]]
The World Bank and UN Habitat estimate, assuming no major economic reforms are undertaken, more than 80% of additional jobs in urban areas of developing world may be low-paying jobs in the informal sector. Everything else remaining same, this explosive growth in the informal sector is likely to be accompanied by a rapid growth of slums.<ref name="whyslums" />

=== Labour, work ===

Research in the latest years based on ethnographic studies, conducted since 2008 about slums, published initially in 2017, has found out the primary importance of labour as the main cause of emergence, rural-urban migration, consolidation and growth of informal settlements.<ref name="Cavalcanti">{{Cite book |url=https://books.google.com/books?id=jrCfugEACAAJ |title=Housing Shaped by Labour: The Architecture of Scarcity in Informal Settlements |last=Cavalcanti |first=Ana Rosa Chagas |date=November 2018 |publisher=Jovis Verlag GmbH |isbn=9783868595345}}</ref>{{page needed|date=October 2024}}<ref name="CAVALCANTI 2017 71–81">{{Cite journal |last=Cavalcanti |first=Ana Rosa Chagas |date=2017|title=Work, Slums, and Informal Settlement Traditions: Architecture of the Favela Do Telegrafo |journal=Traditional Dwellings and Settlements Review |volume=28 |issue=2 |pages=71–81 |issn=1050-2092 |jstor=44779812}}</ref> It also showed that work has also a crucial role in the self-construction of houses, alleys and overall informal planning of slums, as well as constituting a central aspect by residents living in slums when their communities suffer upgrading schemes or when they are resettled to formal housing.<ref name="Cavalcanti" />{{page needed|date=October 2024}}

For example, it was recently proved that in a small favela in the northeast of Brazil (Favela Sururu de Capote), the migration of dismissed sugar cane factory workers to the city of Maceió (who initiated the self-construction of the favela), has been driven by the necessity to find a job in the city.<ref name="CAVALCANTI 2017 71–81" /> The same observation was noticed on the new migrants who contribute to the consolidation and growth of the slum. Also, the choice of the terrain for the construction of the favela (the margins of a lagoon) followed the rationale that it could offer conditions to provide them means of work. Circa 80% of residents living in that community live from the fishery of a mussel which divides the community through gender and age.<ref name="CAVALCANTI 2017 71–81" /> Alleys and houses were planned to facilitate the working activities, that provided subsistence and livelihood to the community. When resettled, the main reason of changes of formal housing units was due to the lack of possibilities to perform their work in the new houses designed according to formal architecture principles, or even by the distances they had to travel to work in the slum where they originally lived, which was in turn faced by residents by self-constructing spaces to shelter the work originally performed in the slum, in the formal housing units.<ref name="Cavalcanti" />{{page needed|date=October 2024}} Similar observations were made in other slums.<ref name="Cavalcanti" />{{page needed|date=October 2024}} Residents also reported that their work constitutes their dignity, citizenship, and self-esteem in the underprivileged settings in which they live.<ref name="Cavalcanti" />{{page needed|date=October 2024}} The reflection of this recent research was possible due to participatory observations and the fact that the author of the research has lived in a slum to verify the socioeconomic practices which were prone to shape, plan and govern space in slums.<ref name="Cavalcanti" />{{page needed|date=October 2024}}

===Poverty===
Urban poverty encourages the formation and demand for slums.<ref name="UN-Habitat 2007 Press Release" /> With rapid shift from rural to urban life, poverty migrates to urban areas. The urban poor arrives with hope, and very little of anything else. They typically have no access to shelter, basic urban services and social amenities. Slums are often the only option for the urban poor.<ref>''Slums of the World: The Face of Urban Poverty in the New Millennium?'' {{ISBN|92-1-131683-9}}, UN-Habitat</ref>{{page needed|date=October 2024}}
[[File:Slum shower jbi.jpg|thumb|A woman from a slum is taking a bath in a river.]]

===Politics===
Many local and national governments have, for political interests, subverted efforts to remove, reduce or upgrade slums into better housing options for the poor.<ref name="grhs2011">[http://www.unhabitat.org/downloads/docs/GRHS.2003.2.pdf "Assessing Slums in the Development Context"] {{Webarchive|url=https://web.archive.org/web/20140105025237/http://www.unhabitat.org/downloads/docs/GRHS.2003.2.pdf |date=2014-01-05}} United Nations Habitat Group (2011)</ref> Throughout the second half of the 19th century, for example, French political parties relied on votes from slum population and had vested interests in maintaining that voting block. Removal and replacement of slum created a conflict of interest, and politics prevented efforts to remove, relocate or upgrade the slums into housing projects that are better than the slums. Similar dynamics are cited in favelas of Brazil,<ref>[http://www.ucl.ac.uk/dpu-projects/Global_Report/pdfs/SaoPaulo.pdf "The case of São Paulo, Brazil – Slums"] {{Webarchive|url=https://web.archive.org/web/20160306145657/http://www.ucl.ac.uk/dpu-projects/Global_Report/pdfs/SaoPaulo.pdf |date=2016-03-06}} Mariana Fix, Pedro Arantes and Giselle Tanaka, Laboratorio de Assentamentos Humanos de FAU-USP, São Paulo, pages 15–20</ref> slums of India,<ref>Philip Reeves (May 9, 2007). [https://www.npr.org/templates/story/story.php?storyId=10089935 "Bid to develop Indian slum draws opposition"] {{Webarchive|url=https://web.archive.org/web/20181106232912/https://www.npr.org/templates/story/story.php?storyId=10089935 |date=2018-11-06}} NPR (Washington D.C.).</ref><ref name="Slum banged">Joshi and Unnithan (March 7, 2005). [http://indiatoday.intoday.in/story/vote-bank-politics-cm-vilasrao-deshmukh-halts-mumbai-slum-demolition-drive/1/194322.html "Slum banged"] {{Webarchive|url=https://web.archive.org/web/20140808053058/http://indiatoday.intoday.in/story/vote-bank-politics-cm-vilasrao-deshmukh-halts-mumbai-slum-demolition-drive/1/194322.html |date=2014-08-08}} ''India Today''.</ref> and shanty towns of Kenya.<ref>Irene Wangari Karanja and Jack Makau (2010). [http://www.irinnews.org/pdf/nairobi_inventory.pdf "Inventory of the Slums in Nairobi"] {{Webarchive|url=https://web.archive.org/web/20130810022349/http://www.irinnews.org/pdf/nairobi_inventory.pdf |date=2013-08-10}} IRIN, United Nations News Service. page 10–14.</ref>

[[File:Principaux Bidonvilles.png|thumb|The location of 100 largest "contiguous" mega-slums in the world. Numerous other regions have slums, but those slums are scattered. The numbers show population in millions per mega-slum, the initials are derived from city name. Some of the largest slums of the world are in areas of political or social conflicts.]]
Scholars<ref name="grhs2011" /><ref>Gerald Suttles (1970). ''The Social Order of the Slum: Ethnicity and Territory in the Inner City''. {{ISBN|978-0226781921}}. University of Chicago Press. Chapter 1.</ref> claim politics also drives rural-urban migration and subsequent settlement patterns. Pre-existing patronage networks, sometimes in the form of gangs and other times in the form of political parties or social activists, inside slums seek to maintain their economic, social and political power. These social and political groups have vested interests to encourage migration by ethnic groups that will help maintain the slums, and reject alternate housing options even if the alternate options are better in every aspect than the slums they seek to replace.<ref name="Slum banged" /><ref>Ahsan Ullah (2002). [http://iussp2005.princeton.edu/papers/50712 "Bright City Lights and Slums of Dhaka city"] {{Webarchive|url=https://web.archive.org/web/20130507043643/http://iussp2005.princeton.edu/papers/50712 |date=2013-05-07}} City University of Hong Kong.</ref>

===Social conflicts===
Millions of [[Lebanon|Lebanese]] people formed slums during the [[Lebanese Civil War]] from 1975 to 1990.<ref>[http://www.unhabitat.org/downloads/docs/GRHS.2003.4.pdf "Slums – Summary of City Case Studies"] {{Webarchive|url=https://web.archive.org/web/20130921055646/http://www.unhabitat.org/downloads/docs/GRHS.2003.4.pdf |date=2013-09-21}} UN Habitat, page 203.</ref><ref>Mona Fawaz and Isabelle Peillen (2003). [http://www.ucl.ac.uk/dpu-projects/Global_Report/pdfs/Beirut.pdf "Slums: The case of Beirut, Lebanon"] {{Webarchive|url=https://web.archive.org/web/20130921060855/http://www.ucl.ac.uk/dpu-projects/Global_Report/pdfs/Beirut.pdf |date=2013-09-21}}, Massachusetts Institute of Technology.</ref> Similarly, in recent years, numerous slums have sprung around Kabul to accommodate rural Afghans escaping Taliban violence.<ref>[https://www.amnesty.org/en/documents/asa11/001/2012/en/ "Fleeing war, finding misery: The plight of the internally displaced in Afghanistan"] {{Webarchive|url=https://web.archive.org/web/20181122054838/https://www.amnesty.org/en/documents/asa11/001/2012/en/ |date=2018-11-22}} Amnesty International (February 2012); pages 9–12</ref>

===Natural disasters===
Major natural disasters in poor nations often lead to migration of disaster-affected families from areas crippled by the disaster to unaffected areas, the creation of temporary tent city and slums, or expansion of existing slums.<ref>[http://www.citiesalliance.org/About-slum-upgrading "Slum upgrading – Why do slums develop"] {{Webarchive|url=https://web.archive.org/web/20130906160759/https://www.citiesalliance.org/About-slum-upgrading |date=2013-09-06}} Cities Alliance (2011)</ref> These slums tend to become permanent because the residents do not want to leave, as in the case of slums near Port-au-Prince after the [[2010 Haiti earthquake]],<ref>[http://www.miamiherald.com/2013/01/08/3173715/three-years-after-haiti-earthquake.html "Three years after Haiti earthquake, loss of hope, desperation"] {{Webarchive|url=https://web.archive.org/web/20131003100844/http://www.miamiherald.com/2013/01/08/3173715/three-years-after-haiti-earthquake.html |date=2013-10-03}} Jacqueline Charles, ''Miami Herald'' (January 8, 2013)</ref><ref>[https://www.telegraph.co.uk/news/worldnews/centralamericaandthecaribbean/haiti/9425214/Slum-eviction-plans-in-Haiti-spark-protests.html "Slum eviction plans in Haiti spark protests"] {{Webarchive|url=https://web.archive.org/web/20181103004246/https://www.telegraph.co.uk/news/worldnews/centralamericaandthecaribbean/haiti/9425214/Slum-eviction-plans-in-Haiti-spark-protests.html |date=2018-11-03}} ''The Telegraph'' (United Kingdom), July 25, 2012</ref> and slums near Dhaka after 2007 [[Bangladesh]] Cyclone [[Cyclone Sidr|Sidr]].<ref>[http://reliefweb.int/report/bangladesh/bangladesh-cyclone-rebuilding-after-cyclone-sidr Bangladesh cyclone: Rebuilding after Cyclone Sidr] {{Webarchive|url=https://web.archive.org/web/20160304073813/http://reliefweb.int/report/bangladesh/bangladesh-cyclone-rebuilding-after-cyclone-sidr |date=2016-03-04}} Habitat for Humanity International (May 6, 2009)</ref>