Zambia's copper resources have not made the country rich. Virtually all Zambia's copper mines are owned by corporations. In the last ten years, they've extracted copper worth $29 billion but Zambia is still ranked one of the twenty poorest countries in the world.

So why hasn't copper wealth reduced poverty in Zambia? Once again it comes down to the issue of tax, or in Zambia's case, tax avoidance and the use of tax havens.

Tax avoidance by corporations costs poor countries and estimated $160 billion a year, almost double what they receive in international aid. That's enough to save the lives of 350,000 children aged five or under every year.

For every $1 given in aid to a poor country, $10 drains out. Vital money that could help a poor country pay for healthcare, schools, pensions and infrastructure. Money that would make them less reliant on aid.