There are so many factors that must be considered before concluding which country is the richest or has lowest poverty rate. Measuring how rich a country is should not be based on GDP per capita. This does not totally prove a country to be rich. There are so many countries like USA, Germany with higher GDP but they still have issues with population.
Determining which country has the lowest poverty rate should also be based on the population of the country. Country with low population and an appreciable higher GDP tends to have lower poverty rate. In fact, there are so many countries with higher GDP but their poverty is still higher and we also have countries with not too low GDP but their poverty rate is low.
Australia is believed to have the lowest poverty rate in the world. Children poverty rate is very low too. Their emergence as the country with the lowest rate is as a result of numerous social intervention programs that are available for citizens