"I felt like a fourth-rate Bono. Later on I felt like a third-rate Bono, and hopefully it'll escalate until I feel like a full-on Bono." Taking a crash course in the economics of international trade, Coldplay's Chris Martin spent a week in Haiti with Oxfam to promote the Make Trade Fair Campaign. Find out how he got on in Chris's Haiti diary. Day 1: En route in the Dominican Republic After a night in the Dominican Republic's capital Santa Domingo, we set off at some ungodly hour this morning. Emily Eavis was there representing Glastonbury festival, along with two workers from Oxfam GB. It felt like those Comic Relief trips you see on TV - Landrovers, mud lanes and slightly red-faced Brits trying to look important. The mountain area where the coffee grows is incredibly lush and beautiful - partly because of the coffee. World coffee prices have plummeted in the past decade, with farmers often selling their crop for less than it costs them to grow it. Yet the price in our supermarkets at home hasn't gone down at all: it's multinationals like Nestlé and Douwe Egbert who are profiting. The Oxfam-supported coffee co-op we visited now gets just $45 for 100 lbs of coffee, but Fair Trade organisations buy the same coffee for $126. So if you pay a few pence more for Fair Trade coffee, the farmers get nearly three times more for their crop - an incredible difference. Back in Santa Domingo, I did an interview for a local radio station. I didn't expect them to know me but bizarrely, Coldplay has had a number one record here. So I talked about Oxfam's work, sang a few songs live. I guess this is why I'm here - because I have access to the media, and I'd rather talk about something like Oxfam in interviews than the colour of my socks. Day 2: Port-au-Prince, Haiti After September 11, everyone's nervous about flying, but I was bricking it as we boarded the tiny plane to Haiti. I really don't want to die until we finish this album. After a hectic day's interviews at local radio and TV stations in Port au Prince, Haiti's capital, we went to Mardi Gras. It was bonkers. The noise, the dense crowds, the sound systems, the costumes. There was a man dancing with live snakes, costumed men using whips to clear the crowd out of the way of the carnival floats, policewomen touting Uzis. This very nice girl handed me a condom, which I thought was pretty forward. But then she walked off, so it must have been a safe sex thing... Day 4: Dondon After another long, bumpy drive which felt as if somebody was hitting you on the bum with various types of rock, we went to another coffee co-op to see men putting the coffee out to dry in the sun on concrete patios, and women sorting the beans by hand, picking out the best quality ones for export. This co-op was just three years old, and still very basic. The women told us how they can't afford to send their children to school, or buy even basic health-care. We also learned about a plague of insects that is destroying the coffee crops, and it all seemed so bleak. I've never seen anything like this before. I felt homesick. I just wanted to retreat into my little bubble of being a pop star and worrying about my reviews. I was talking to a guy at lunchtime and I said I didn't have any solution to these problems, and he said, "Of course you don't. You're a singer." And I thought, "You're right, what the hell am I doing here in a bandana trying to look like Axl Rose?" Yolette Etienne, the inspiring Haitian woman who heads Oxfam here, keeps telling me to look for the hope. "We've just got to do things bit by bit. You've got to see the good that these little projects are doing." Day 7: Artibonite Valley Drove back through the dust bowl to the lush, green rice fields of the Artibonite valley. There are 32,000 acres of rice fields here - enough, if the farmers had the right machinery and technical assistance, to feed the whole of Haiti. Instead, they are struggling to compete with the cheap, American rice that is sold in all the markets here. This rice dumping is an example of what Oxfam means when it talks about unfair trade. Haiti has been forced to drop all restrictions on imports, making it one of the freest markets in the world, as well as one of the poorest countries. So it is flooded with surplus rice grown by heavily subsidised farmers in the US, and many of its own rice farmers are now moving to the already overcrowded slums in the cities in search of work. Haiti could feed itself. Instead, this area could soon be abandoned and turn to dust too. Day 8: In transit More small planes, more airports, and the long journey home. I came out here feeling like a fraud, but I now feel informed, more able to get the issues across. I've had so many facts and figures about coffee and rice, import and export tariffs, World Trade Organisation rules and World Bank loan conditions. It's very complex, but for me it all boils down to fish and chips. In an ideal world, one person would have fish, another would have potatoes, and you'd trade so you both got fish and chips. But you need to be able to trade on equal terms. To succeed, a country has to be allowed to produce things for itself, both to feed its own people and to have something to trade with. But because of unfair trade rules, loan conditions and corrupt governments, developing countries aren't being allowed to progress. We force places like Haiti to accept products they don't need: their agriculture is being destroyed by things like rice dumping. Meanwhile, the European Union and the United States protect their economies by refusing to let in too many goods from developing countries. It's indefensible. American rice farmers don't need the money they get from Haiti - they've got subsidies. As for the coffee prices, if a few companies were slightly less greedy, the people at the bottom would have an awful lot more. Heaven and Hell I didn't expect Haiti to be like this. Some of it is like hell on earth, other bits are so beautiful. No one I talked to here wanted their children do the same as them - they hoped they would leave the country and send money back. That's sad. But I loved meeting people like Yolette who are working to change things, to do something practical. They're trying to help Haiti grow from the bottom up, and we can do our bit by buying Fair Trade products, as well as pressuring politicians to change this insanity, to make trade fair. -Chris Martin