It’s hard to know for sure what the GDP of poorer countries is, because their economic statistics are often missing or unreliable.
Researchers from Brown University in Providence, Rhode Island, think they have come up with a solution by measuring how much light a country shines out at night, as seen from orbit.
In these pictures see how the light power of different regions compares.
The artificial lighting shown in this composite satellite image shows the uneven spread of wealth across the world.
As countries develop and grow economically they build more infrastructure, including street lighting, and people turn on more lights at night.
It is suggested that that the night-time light output of a nation as seen from space correlates to its GDP.
This way of assessing economies could be useful where other data is minimal or misleading.
(Image: NASA)
This is the distribution of night-time lights in North America, one of the richest regions in the world.
The US has the highest GDP in the world, currently standing at $47,000 per person.
(Image: NASA)
Western Europe is brightly illuminated.
This image clearly shows that the cities of major Europe are along the coasts but there are roads, lighting and population centres across the entire region.
There is also a high concentration of cities on the river Nile, downstream of the Aswan dam.
(Image: NASA)
This image shows the densely populated areas on the coasts of South America, and in northern Colombia and Venezuela.
More inland areas are relatively sparsely lit.
(Image: NASA)
Asia is a mix of developed and rapidly developing countries, with India and China’s speedy economic growth attracting particular attention.
Also visible on this map are the dense light emissions of Japan.
(Image: NASA)
