But what I think the writer is trying to say here the economy (value of the total goods produced which is reflected in money circulated) is too small to support the population of zambia.
Why is the economy small? Answers like, "because they are poor," are forbidden.
A more useful question would be: was the growth of Zambian economy slow historically? If yes, why?
The politics isn't perfect and economic diversification from mining is still only in it's infancy, but the trends are pointing in the right direction.
Maybe, the small amount of money spend per person indicates that the government doesn't have sufficient money to invest in development of the infrastructure and human resources required for creating a developed economy.
If you look at South Africa's public debt, it is 43.3%[1] of their GDP. In contrast, Zambia's is 20%[2]. Maybe, what Zambia needs is to secure more loans from organizations like World Bank and invest
1 - http://en.wikipedia.org/wiki/Economy_of_South_Africa 2 - http://en.wikipedia.org/wiki/Economy_of_Zambia
Most Western economies grew larger by looting (the crusades, the Americas, Africa, Asia, black slaves, etc). Without this huge boost of stolen or acquired for pennies resources, slave labour, stolen land to build on, etc, they would not have funded their industrial revolutions and their subsequent prosperity.
Zambia, being poor and with little might, had nothing to loot. They got looted themselves, first by third party countries directly and then by their companies (and their pals they placed in power).
Corruption saps a country of it's wealth, enabling a small minority to enrich themselves. My wife comes from a country that has never had any sort of war, yet is about on par with most west-African countries who have seen decades of war. When there's systemic corruption, encouraging any sort of investment is impossible, and wealth doesn't stay in the country.