People openly live on the streets of the world’s major urban centres – from Cairo to Washington DC – a disconcerting reminder of homelessness. While some maintain homelessness is a solvable problem, others conclude that the condition is an enduring feature of modern urban landscapes.

Homelessness was once considerably less visible. In 1950, for example, 70% of the world’s population of 2.5 billion was spread out across rural areas. Housing problems, far removed from urban centers, were largely unnoticed. Today, most of the world’s population of 7.6 billion, 55%, is concentrated in urban centers, in close proximity to the politically influential and economically well-to-do.

Based on national reports, it’s estimated that no less than 150 million people, or about 2% of the world’s population, are homeless. However, about 1.6 billion, more than 20% of the world’s population, may lack adequate housing.

Defining homelessness

Obtaining an accurate picture of homelessness globally is challenging for several reasons. First, and perhaps most problematic, is variations in definitions. Homelessness can vary from simply the absence of adequate living quarters or rough sleeping to include the lack of a permanent residence that provides roots, security, identity and emotional well-being.

The absence of an internationally agreed upon definition of homelessness hampers meaningful comparisons. The United Nations has recognised that definitions vary across countries because homelessness is essentially culturally defined based on concepts such as adequate housing, minimum community housing standard or security of tenure.

Second, many governments lack resources and commitment to measure the complicated and elusive phenomenon. Authorities confront a dynamic situation with frequent changes in housing status, and many communities have not established accurate trends of homelessness.

Third, homelessness is often considered embarrassing, a taboo subject, and governments tend to understate the problem. Obtaining accurate numbers is difficult, especially in developing countries. In Moscow, for example, officials report that the homeless number around 10,000, while non-government organisations claim that as many as 100,000 live on the streets.

Also, in the Philippines capital of Manila, reported to have the largest homeless population of any city in the world, estimates vary from several million to tens of thousands. In the world’s billion-plus populations, China and India, reported numbers of homeless are 3 million and 1.77 million, respectively, rates of 0.22% and 0.14% – on par with levels reported by many wealthy developed countries. Given their levels of socio-economic development, the Chinese and Indian rates of homelessness appear unduly low.

Fourth, many of the homeless are reluctant to be enumerated or registered. Homeless youth often avoid authorities who may contact parents or place them in foster care. Some parents may not wish to be labeled as homeless out of fear of losing custody of children. Also, some homeless persons, especially those suffering from mental disorders or substance abuse, fear arrest or confinement at a medical facility for treatment.

Acknowledging that national definitions of homelessness vary and the limitations in available data and statistical measures, the highest levels of homelessness, typically double-digit rates, are in the least developed nations, failing states and countries in conflict or suffering from natural disasters. Haiti, Iraq, Nigeria, Somalia, South Sudan and Syria, have large numbers of internally displaced persons, many living in makeshift temporary housing, shantytowns or government shelters.

Homelessness rates reported in most developed countries, including those in shelters and on the streets, are comparatively low. The proportions of homeless among OECD countries, for example, are below 1%. The highest rate, nearly 1%, is in New Zealand, where more than 40,000 people live on the streets or in emergency housing or substandard shelters.

Strategies: Definitions and policies on homelessness are mixed among and within nations, as some governments lump the problem with poverty; homelessness does not exceed 1 percent in wealthy nations while rates in poor nations can go into the double digits. Source: OECD

Ten countries, including Italy, Japan and Spain, report homeless rates of less than a 10th of 1%. While rates in wealthy developed nations are small, they represent large numbers of homeless persons, more than 500,000 in the United States and more than 100,000 in Australia and France.

Trends in homelessness among OECD countries with available data are mixed. In recent years rates of homelessness are reported to have increased in Denmark, England, France, Ireland, Italy, the Netherlands and New Zealand, while decreasing in Finland and the United States.

National levels of homelessness are typically lower than those of their major cities. For example, while the US rate of homelessness is 0.17%, the rate in its capital, Washington, DC, is more than seven times higher at 1.24%. The majority of homeless in the United States, 60%, are male, with rates nearly twice as high as those of women.

Housing too expensive

Causes of homelessness across countries are multifaceted, though some factors stand out, including shortages of affordable housing, privatisation of civic services, investment speculation in housing, unplanned and rapid urbanisation, as well as poverty, unemployment and family breakdown. Also contributing is a lack of services and facilities for those suffering from mental illness, alcoholism or substance abuse and displacement caused by conflicts, natural disasters and government housing policies. In some cases, too, homelessness leads to alcoholism, substance abuse and mental illness.

In many countries the prices to buy or rent homes are relatively high and rising faster than wages. Urban “gentrification” leading to rising property values and rental rates push low-income households into precarious living arrangements including slums, squatter settlements and homelessness.

Even people with jobs sometimes cannot afford adequate housing on minimum wages. One recent study, for example, found that nowhere in the United States can someone who works 40 hours a week at the federal minimum wage of $7.25 an hour afford a one-bedroom apartment at fair market rent. To afford a one-bedroom apartment at the average fair market rate without paying more than 30% of one’s income, a person must earn at least $16.35 an hour.

In many cities, growing homelessness is straining resources for social workers and shelters. When officials try to open new facilities or provide services for the homeless, they encounter financial constraints as well as resistance from the public and private enterprises in many neighborhoods, which consider homelessness burdensome and bad for business.

Measures to keep the homeless away, on the move and out of sight include laws banning loitering, noise projection, panhandling, and public feedings/services for the homeless, panhandling or begging; restrictions on camping, sleeping in vehicles; or sitting or standing in public places; limits for can and bottle refunds; and studs, spikes and arms in the middle of benches. Law enforcement officials and security personnel generally lack mandates or specialized training to address homelessness. The only recourse is ordering people move on to another locale.

Many international agreements, declarations and development goals have been adopted stressing the basic human right to adequate, safe and affordable housing. Also, there are no shortages of reports, policy recommendations and efforts to address homelessness including public housing schemes for the poor, giving stable housing first to the homeless, land and agrarian reform, promulgation of laws that protect women’s right to adequate housing, creation of shelters in urban centres, and integrated rural development to prevent involuntary migration to cities.

However, the continuation of homelessness, especially among the wealthy countries, reflects denial and the lack of political will to address poverty and many other issues. Homelessness men, women and children will likely remain an accepted feature of modern urban life for the foreseeable future.

This article first appeared on Yale Global Online.