Summary: Determining levels of homelessness in any one country is difficult, and comparing it across multiple countries is exceptionally hard. Official statistics are often unreliable, or counted in different ways. To compare real levels of homelessness between countries, it can help to consider contributing factors more closely than the official numbers only.

Homelessness can result from drug abuse, domestic violence, family breakdown and other factors, but housing affordability might be one of the most important aspects. Around the world, homelessness has typically followed housing affordability issues and a lack of employment.

To make sure we're comparing similar situations, our analysis looked at the top 21 highest ranked countries (minus Liechtenstein) in the 2016 Human Development Index rankings. Key findings from the 20 countries analysed: By official counts, Australia has a disproportionate number of homeless compared to economically equivalent countries, with 0.43% of people being counted as homeless. This is among the highest levels of all developed countries. However, this is most likely a result of the broad definition of "homeless" used by the Australian government. Other countries that used the same definition would arrive at much higher numbers than they do.

Australia is the fourth wealthiest country by income alone, with a mean household income of $64,338 in 2016. However it's also the fourth most expensive, with the fourth highest Consumer Price Index (CPI). However, this mean household income doesn't account for variations in income inequality between countries or different types of household.

To get a more accurate picture relative to other nations, we've used international dollars ($intl PPP) for comparisons. This helps adjust for differences in purchasing power and exchange rate. In $Intl PPP, Australia is the twelfth wealthiest nation.

for comparisons. This helps adjust for differences in purchasing power and exchange rate. In $Intl PPP, Australia is the twelfth wealthiest nation. The vast differences in housing affordability between different parts of the same country, as well as mortgage regulations and other factors, can make it difficult to compare housing affordability "like for like" between different countries. This analysis uses the Numbeo property prices index , averaged for major cities within each country, to get a general overview of housing affordability across entire countries.

Read another analysis by finder.com.au: Australian Workplace Satisfaction & Average Annual Salary Analysis

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Netflix Australia vs Netflix US TV Show Library Comparison Country 2016 HDI Score Population (2016) Est. number of homeless Est. homelessness ratio GDP per capita, PPP (constant 2011 $Intl) Property prices index Norway 0.949 5,232,929 6,259 0.14% 63,811 1.87 Australia 0.939 24,127,159 105,237 0.43% 44,414 1.77 Switzerland 0.939 8,372,098 n/a n/a 56,625 1.76 Germany 0.926 82,667,685 284,000 0.35% 44,072 1.76 Denmark 0.925 5,731,118 10,000 to 15,000 0.11% 45,686 1.87 Singapore 0.925 5,607,283 n/a n/a 81,443 0.72 Netherlands 0.924 17,018,408 31,000 0.19% 47,128 2.41 Ireland 0.923 4,773,095 7,148 0.15% 62,828 1.62 Iceland 0.921 334,252 n/a n/a 45,276 1.45 Canada 0.92 36,286,425 235,000 Up to 0.5% 43,088 2.46 United States 0.92 323,127,513 610,042 0.18% 53,273 1.32 (Seattle) to 13.15 (Detroit) Hong Kong 0.917 7,346,700 1,400 0.02% 54,279 0.41 New Zealand 0.915 4,692,700 300 <0.01% 35,269 1.23 Sweden 0.913 9,903,122 34,000 0.36% 46,441 1.89 United Kingdom 0.909 65,637,239 250,000 0.38% 38,901 0.62 (London only) Japan 0.903 126,994,511 25,000 0.02% 38,240 1.03 South Korea 0.901 51,245,707 5,000 to 10,000 0.01% to 0.02% 34,986 0.81 Israel 0.899 8,547,100 1,831 0.02% 32,613 1.18 Luxembourg 0.898 582,972 1,533 0.28% 97,019 1.46 France 0.897 66,896,109 141,500 0.21% 38,059 1.35 Belgium 0.896 11,348,159 10,000 <0.01% 41,946 2.20 Finland 0.895 5,495,096 7,572 0.13% 39,423 2.10 Austria 0.893 8,747,358 5,811 <0.01% 44,144 1.50 Slovenia 0.89 2,064,845 4,000 0.20% 29,803 1.20 Italy 0.887 60,600,590 48,000 0.08% 34,620 1.19 2016 HDI Score: The 2016 Human Development Index, according to the United Nations.

Population: The population of each country in August 2017, according to World Bank estimates, extrapolated from each country's census data.

Estimated number of homeless: Estimated of the number of homeless in each country, generally according to the most recent official estimates available.

Estimated homelessness ratio: Percent of the total population, in the year of the relevant official count where applicable, that was counted as homeless.

GDP per capita PPP ($Intl): According to the World Bank, the mean per capita GDP of each country in international dollars. International dollars are a hypothetical unit of currency, equivalent to US dollars adjusted for purchasing power parity and exchange rates in a given year, in this case 2011.

Property Prices Index: The Numbeo Property Prices Index, which is a composite of factors including property prices, mortgage affordability and rental prices. The lower the number, the less affordable it is. In this case the national figures were arrived at by averaging all available city information. Note that these only include property prices in cities, not regional areas, and may not be representative of all cities in the country.

Key findings

Homelessness and inadequate housing is a problem in all countries, even those such as Singapore, which do not officially have a homeless population. There's a lot to learn by considering the data in detail.

Official homelessness statistics are generally inaccurate

Official homelessness statistics should not be considered accurate when comparing countries. For example, Australia counts those living in unsafe or overcrowded properties as homeless, while Hong Kong only counts people who are actually sleeping on the streets. Austria, meanwhile, gets its precise figures by looking at the number of people who have officially registered as homeless and Singapore doesn't officially count its homeless population at all.

The figure of 610,042 homeless people in the USA refers to the count on a single night in January 2013, but unofficial estimates put the number of homeless in the USA at between 1.6 million and 3.5 million. And in New Zealand, the figure of 300 is generally thought to only estimate the number of homeless sleeping rough in urban areas, but not the potentially several-thousand living in improvised shelters in rural areas.

Also, each country's official statistics were gathered at different times. As economic conditions change, the rate of homelessness can change year to year. Official statistics cannot be used to accurately compare homelessness between countries.

Inadequate housing is as much a problem as homelessness

You might have noticed that Hong Kong only has an estimated 1,400 homeless people, despite exceptionally high property prices. This number doesn't account for the estimated 100,000+ who live in so-called "coffin homes," on rooftops or in other inadequate housing. In Australia, those types of living situations would have been counted as homeless.

Australia's comparatively high homeless count might be a more accurate reflection of the situation, and doesn't necessarily mean that Australia has more homeless people, just that it counts them more accurately.

Property prices don't necessarily reflect typical income or the overall cost of living

It's possible to find severe disparities between housing prices and the general cost of living, especially on a city-by-city basis. Fast food might not be that much more expensive in Seattle than Detroit, but houses certainly are.

A similar picture can be seen around Australia, between the capital cities, and between city and regional areas. Housing is very different to anything else, and should not be considered purely on general economy-wide factors. Instead, one needs to take very a close look at its individual variables, and consider the impact of specific factors like ongoing incentives to invest in property.

Property prices and homelessness need to be considered on a very local level

All around the world, the majority of homelessness is concentrated in cities. This also tends to be where property prices are highest, and space is more scarce. Affordable housing is only good as its location, but unfortunately it's most needed where space is at a premium and property prices are highest.

Affordable housing in ghost towns won't help alleviate homelessness, so it's not enough to simply provide housing. The housing needs to provide access to jobs and a suitable range of living essentials. Unfortunately, this also tends to be where property prices are the highest, making it more expensive to provide and less likely that it will be constructed.

The ideal solution is likely to be a multi-pronged approach, involving construction of affordable housing in the high-demand areas where it's needed most, as well as continuing investment in jobs growth in lower-demand areas. Essentially bringing both houses and jobs where they're needed most.

Other takeaways

Simply by measuring the homeless population more accurately than almost any other country in the world, Australia is taking solid steps to address the issue. However, there's still plenty of room for things to get worse. Australia is far from the least-affordable country in the world, and concerted steps are needed to help things get better, instead of slipping further.

It's also important to remember that the homeless population is always changing, and it's also important to consider the at-risk population (which Australia already does), referring to those who are one financial disaster away from potentially losing their homes. Relatively few people are chronically homeless and sleeping rough, compared to the total number who will be homeless at some point in time.

Most homelessness takes the form of couch-surfing, sleeping in cars, overcrowded properties and other substandard living arrangements. This, coupled with the difficulties involved in counting the homeless population, means census data and official homelessness figures may be of limited use when comparing countries.

As such, it may be more useful to consider the homelessness risk factors, such as unaffordable housing, lack of employment opportunities and others, as a more accurate indication of the real homeless population in a given area, and to consider these when allocating resources.