CHARLOTTE, N.C. To estimate the economic impact of last week’s Democratic National Convention, Charlotte tourism officials are hiring an outside group, Tourism Economics, to conduct a two-month study.

The Charlotte Regional Visitors Authority usually makes visitor spending projections for conventions and other large events.

But an Observer investigation found the CRVA’s research department has made wildly inflated estimates of economic impact for past events, sometimes contradicting itself.

In response, the CRVA’s new chief executive, Tom Murray, has pledged more accurate reporting. The outside consultant is part of that change.

“We chose this route to ensure we provide the most comprehensive, credible and clear data,” CRVA spokesperson Kimberly Meesters said in an e-mail.

When Charlotte landed the DNC, the CRVA first estimated the event could generate $75 million in visitor spending. The tourism authority also said the event could produce a similar economic impact to the 2008 DNC in Denver, which was pegged at $134 million.

The DNC attracted as many as 35,000 people to Charlotte, including 15,000 journalists and 6,000 delegates.

Not only is the DNC the city’s largest convention, it could produce more visitor spending than all other conventions in a year combined. But some economists warn that because political conventions are so large, they “crowd-out” some regular commerce.

During the DNC, for instance, thousands of uptown workers stayed home or worked at different locations. Some stores and restaurants closed, worried about losing their regular customers.

It’s unclear whether the consultant will look at what business was lost during the DNC or whether it will focus on the new dollars that came to the Charlotte region.

Pennsylvania-based Tourism Economics is considered an expert in doing economic impact reports, Meesters said, and its models are used by more than 100 cities.

The study was commissioned by Charlotte Center City Partners, Charlotte Regional Partnership, Charlotte Chamber and the CRVA.

The CRVA doesn’t yet know how much the report will cost.

Murray is currently reorganizing the CRVA’s research department, which had previously been under human resources and was seen as a marketing tool. Research will now be in accounting.

The CRVA is also looking for a new research director after Michael Applegate left for a senior sales position with the Cabarrus Convention and Visitors Bureau.