A leading think-tank has claimed that a "weak" devolution settlement in Wales has left the country poorly positioned to deal with economic problems.
There have been calls for the assembly to have more powers
The Institute of Welsh Affairs (IWA), and that the Welsh assembly needs more power if the administration is to achieve its ambitions.
Produced jointly by the IWA and the Constitution Unit at University College London, the report also suggests that the current set-up is a poor model for the English regions to follow.
Writing in the report, Second Term Challenge, Professor Phil Cooke says Wales' relatively weak devolution settlement has left it unable to formulate innovative policies to deal with the loss of manufacturing jobs.
Professor Cooke, an expert in regional economic development based at Cardiff University, also argues that the Scottish Parliament, with its extra powers, has been able to develop innovative policies.
It has developing a knowledge-based economy to counteract a loss of traditional manufacturing jobs, he says.
The publication takes a critical view of the devolution settlement, claiming that Wales has failed to match Scotland's success, and that the "weak" arrangements do little to encourage "dynamic and experimental policy making".
The IWA says that Wales has been unable to form innovative policies to deal with the downturn in manufacturing, and that Welsh business policy lacks both innovation and integration.
Former Welsh secretary Ron Davies - the man dubbed "the architect of the assembly" - told BBC Radio Wales he agreed with Prof Cooke that the assembly had failed to deliver - but not because of lack of powers.
"I think he has described accurately the way that economic policy, particularly, has gone over the last couple of years," he said.
"But I do take issue with him on his analysis, because I don't think the causal link which he is suggesting between the nature of the settlement and the policy outcomes has been established."
And, he added : "I think his analysis in assuming that it is down to the nature of the settlement is flawed.
Lord Richard of Ammanford is heading the review
"Ministers could have been far more ambitious - with regard to the National Botanic Garden, for example. If they had wanted to, they could have intervened and saved it."
Mr Davies said he was in favour of a Scottish-style parliament, and added : "I think we have moved on from where we were in 1997, and now is the time to have a far more expansive parliament here in Wales.
Alun Cairns, the Conservatives' spokesman on economic affairs in the assembly, described Prof Cooke's conclusions as "a pretty damning report" on the Welsh Assembly Government.
"Not much progress has been made over the last four years," he said.
The future of the assembly was under the spotlight at the weekend, with First Minister Rhodri Morgan addressing Labour Party members at a conference in Cardiff.
Mr Morgan said any further powers for the assembly would not necessarily have to be approved in a referendum.
He proposed a special party conference in July 2004 to discuss the party's response to the Richard Commission report, expected in the new year.
Mr Morgan has avoided making his views known on the topic of extending the assembly's powers.
In Saturday's speech, he said it was a mistake to assume the Scottish Parliament model was the only way forward for Wales.
The system in Northern Ireland was another example which could be considered, he said.