The report, commissioned by Edinburgh City Centre Management (ECCM), examined the possible impact of congestion charging on city retailers.
It predicts that if the £2 toll proceeds in 2006 and no further transport measures are introduced, city centre retail spending will fall by four per cent - a retail loss of £38 million a year. The study emphasises that public transport should be improved before the toll is introduced.
Edinburgh City Council has pledged better bus services and park-and-ride sites by 2006. Further improvements that depend on revenue generated by the charge, including a tram service, will be operational by 2009. If these plans go ahead, the study agrees that a temporary fall in retail spending should be reversed.
ECCM chief executive Gordon Reid said: "This report makes it clear that congestion charging is a challenge for retailers but it offers evidence that any negative impact can be overcome."
Council leader Donald Anderson added: "It shows that, with public transport improvements, the fortunes of the city centre should not be dented."
Proposed Congestion Charge Scheme for Edinburgh can be viewed via www.PlanningResource.co.uk.