The relationship between local wealth and the number of night lights is strong in most countries in the sample. The study has potential applications in other areas, says Sebastian Schutte, a fellow at the University of Konstanz’s Zukunftskolleg. It is also applicable to other areas besides urban centers. Its method can be easily implemented and applied to various other areas. The results are impressive. It is important to remember that the results are preliminary.
Benefits
The changing emission patterns of night lights can reflect differences in resource investments and local economic development. These data are extremely reliable, allowing the prediction of local wealth without relying on other sources of information. This method of analysis is particularly valuable for countries where previous surveys are impossible or impractical. It can be used to generate predictions for countries that are unknown to researchers, making it a powerful tool for assessing the economic effects of violent conflict.
It has been shown that nighttime light emissions are a good proxy for household wealth. Even though nighttime lights have limited predictive power in cross-country studies, they have been associated with many other indicators of wealth. For example, a doubling of household wealth is associated with an increase in primary school attendance of three out of every 100 children. In addition, an increase in household wealth is associated with a doubling of adult education, a doubling of average age at first birth, and a doubling of the number of women who are assisted during childbirth.
These results are promising. The use of satellite data provides a way to address missing data in rural areas and compare different wealth levels across different countries. However, there are several caveats when using night light emissions as a proxy for local wealth. The relationship between nightlight emissions and wealth is not consistent globally, so differences in national wealth should be taken into account. For example, in Sweden, 99% of populated areas are illuminated at night, whereas in the US, fewer than five percent of populated areas are lit up.
Methods
There is a strong correlation between household wealth and the amount of nighttime lights in a grid cell. The association between nighttime lights and total wealth is strong, but it becomes weaker as you move down in area units. For example, the relationship between nighttime light emissions and poverty is less clear at the smallest possible spatial unit – the pixel. However, when you move up in spatial scale, this association becomes stronger, and it is more apparent when you consider the entire US state and the size of a metropolitan area.
Nighttime light emissions are also indicative of household wealth and other social outcomes. A change in household wealth was related to higher primary school enrollment, higher adult education levels, and a lower infant mortality rate. These associations remained even after accounting for differences between the countries’ characteristics over time. These results suggest that nighttime light emissions are a useful tool to predict local wealth and poverty. They also have the potential to measure the impact of economic growth on household wealth.
There are many ways to measure nighttime illumination, but the most promising method is to analyze it at a fine-grained level. This method uses geo-referenced data to map out nightlights in grid cells. Researchers report that the correlation between nightlight emissions and local wealth is strong in most countries in their sample. It may even be applicable to other areas, such as cities. For instance, it can be used to map the economic situation of entire nations or even countries in their regions.
Results
Studies have shown that nighttime illumination is a reliable proxy for local wealth in developing countries. However, most of these studies have been at coarse resolutions and using large grid cells. Now, researchers have used fine-grained data from the Demographic and Health Survey to examine the relationship between nighttime light emissions and local wealth. They found that higher rates of electrification were positively associated with local human development. The findings suggest that the use of night lights to predict wealth in developing countries may have wide-ranging implications.
Researchers Nils B. Weidmann and Sebastian Schutte use more than 34,000 measurement points across 40 countries to compare survey-based wealth indicators with the nightlight emissions in a single city. The results show that the association between nighttime light emissions and local wealth is stronger when comparing the results of the two measures. Moreover, this association was seen to be robust when using data from the DHS and the full census.
These results also show that ethnic groups represented in the rebellions are generally more prosperous than non-rebels in the area. This is consistent with the fact that nighttime light increases in those regions with higher GDP. Therefore, the results of using night light emissions to predict local wealth are promising. If more social scientists learn to use spatial data, they may be able to incorporate the data into their analyses. With these data, the social sciences will be able to better predict local wealth.
Importance
Night light emission patterns are a proxy measure of human development at the local level. During periods of post-conflict reconstruction, nightlight patterns are similar to within-country regressions, although differences across countries may be evident in infant mortality. These findings highlight the importance of night light patterns in predicting local wealth. However, a larger study is needed to explore the role of night light emissions in predicting local wealth.
Nighttime light emissions are indicators of household wealth. The correlation between light levels and wealth varies across countries. It has been shown that wealth in one country is associated with a higher proportion of electricity-free households. It also predicts the proportion of children in primary school and the proportion of adults with some level of education. It also predicts infant mortality, a decrease in infant mortality, and an increase in professional assistance during childbirth.
Researchers have shown that nighttime illumination is a reliable indicator of wealth in other areas. In most countries in the sample, nightlight emissions are highly correlated with overall wealth. The results show that this association increases with GDP per capita, even at a very low level of agricultural value added. The relationship is stronger when the spatial units are smaller. For example, Chen and Nordhaus used US state-level data to estimate wealth in metropolitan areas. However, they found that these findings apply to other areas as well.
Reliability
This study has shown that the relationship between night light emissions and local wealth is strong. The study used satellite data to map light emission patterns and assigned them to geographic coordinates. The resulting maps show that higher levels of light emission are related to greater wealth. In Pakistan, the city of Hyderabad emits the most light and has a prosperity index value of 4.54, while regions in poorer countries emit almost no light.
Among the three variables, urbanization and electrification may be more reliable than nighttime lights, but their spatial resolution is relatively high. The study captures activity in all households in a given spatial unit. It is possible that urbanization and electrification may be more reliable indicators than nighttime lights, but it is unclear whether or not they will be reliable determinants of local wealth.
Nevertheless, the results indicate that the association between light and wealth is not statistically significant, although it is higher than those in other studies of developing countries. Regression R2 in Namibia is only 42.1%, while in other developing countries, R 2 is 52.7%. In contrast, Wedmann and Schutte’s study found lower than average explanatory power. The results of the present study indicate that this association may be weak and requires further research.
Limitations
The use of satellite images of the night light is limited by the late time of the satellite overpass, which prevents anthropogenic light emissions from being detected after 1:30 am. It is possible to detect areas with little light by observing them around this time, but it is unlikely to be accurate. In both developed and developing countries, the “unlit” infrastructure consists of settlements with electricity, which produce insufficient light to measure. In addition, it is difficult to measure light emissions at an earlier overpass due to intentional nightlight reductions.
In the past, researchers have used economic predictors to predict local wealth and poverty. The use of GDP as a proxy for wealth has been shown to be highly accurate in countries with measurable lighting, but it has limitations in areas where there is little or no lighting. Satellite data of nighttime light emissions can be used as an alternative source of data. Such data can provide a more accurate picture of wealth and poverty, which can be valuable in gauging the effects of violent conflict on a local economy.
Researchers have demonstrated that the use of night lights as a proxy for wealth in developing countries is possible and that these are highly accurate predictors. The use of these estimates can help in predicting new locations within previously observed countries and generate predictions for nations that are not yet observable. The method may be applied to a variety of other areas, including cities, towns, and villages. This new method can be used in a wide variety of applications.
