"So tell me," an old school friend asked, "if the demand for chocolate is so high, why are cocoa farmers so poor?"

We were sitting in the local pub, just days after I returned from a trip to the Ivory Coast, filming a CNN documentary about child labor and poverty in the chocolate industry.

Two years after CNN's Freedom Project exposed Chocolate's Child Slaves, it was time to return to the cocoa plantations to unwrap the chocolate supply chain, to investigate what progress has been made to stop child labor and to explore how farmers can get more money for their beans.

My friend didn't know what he was letting himself in for. The answer to his question is neither simple nor short - and "cocoa-nomics" has become something of an obsession of mine.

The chocolate industry is worth an estimated $110 billion a year, and yet its key commodity is grown by some of the poorest people on the planet, in plantations that can hide the worst forms of child labour.

Accurate figures are impossible to come by, but up to 800,000 children are thought to work in the cocoa sector across the Ivory Coast; children who are both a symptom of and a self-perpetuating factor in a much wider problem - poverty.

Read - Cocoa-nomics: Why chocolate really doesn't grow on trees

Previously:
Do you put your ethics where your mouth is?
The fair trade chocolate challenge
The bitter truth behind the chocolate in your Easter basket