The Pacific Network on Globalisation, PANG, says Tonga's economic decline shows the negative impact of joining the World Trade Organisation.
Tonga's economy is in dire straits and part of the problem, according to PANG, is the tax changes made when it acceded to the WTO four years ago.
An economic development forum is being held in Nuku'alofa today to come up with solutions to the economic malaise.
PANG's Adam Wolfenden says the problems affecting the economy are complex but big cuts to tariffs made by Tonga to meet WTO requirements haven't helped, while there has not been a compensatory lift in foreign investment.
He says it sends a message to other Pacific countries in the process of acceding to the WTO.
"The fact that they are a long way from markets. They have infrastructure that isn't always necessarily of the best. There's a small population. All of these are the main factors which determine where someone invests, not necessarily a regulatory regime, which is WTO consistent. So I think these countries really need to thinking a bit more outside the box in terms of how they structure an economy around what the needs of the Pacific are and those people are."