1. The median annual household income worldwide is $9,733 and the median per-capita household income is $2,920.
2. There are vast differences between more economically developed countries and those with developing or transitional economies.
3. Gallup's income measures are strongly associated with the proportion of adult residents in each country who say they are employed full time for an employer.
The article provides a comprehensive overview of the global median household income and its disparities across different countries. The data used to calculate these metrics was collected by Gallup between 2006 and 2012 in 131 populations, making it relatively up-to-date. The article also mentions that the estimates of household income were expressed in international dollars, created using the World Bank's individual consumption PPP conversion factor, which makes them comparable across all 131 countries.
However, there are some potential biases present in the article that should be noted. Firstly, the article does not provide any evidence to support its claims about the disparities between more economically developed countries and those with developing or transitional economies. Secondly, while it mentions that Gallup’s income measures are strongly associated with the proportion of adult residents in each country who say they are employed full time for an employer, it does not provide any evidence to back this claim up either. Thirdly, while it mentions that “traditional economic indicators” such as per-capita gross domestic product or gross national income may be insufficient for characterizing a population’s quality of life, it does not explore any counterarguments or alternative perspectives on this issue.
In conclusion, while this article provides a comprehensive overview of global median household incomes and their disparities across different countries, there are some potential biases present that should be noted when considering its trustworthiness and reliability.