Statement: The city of San Diego “Lost 1,000 conventions & events in last two years,” due to the lack of a San Diego Convention Center expansion, San Diego Mayor Kevin Faulconer tweeted June 12.

Determination: False

Analysis: The future of the long-delayed waterfront expansion to the San Diego Convention Center almost brightened this week, but was ultimately delayed again when the San Diego City Council declined to set a special election for the mayor’s expansion plan.

San Diego Mayor Kevin Faulconer had been working to put a citywide hotel-tax increase before voters this November to pay for a convention center expansion supporters say is needed to meet demand and spur economic growth. The proposed tax hike would also pay for road repairs and homeless services.

Despite the City Council’s move to quash a special election, the same plan or a version of it could still go before voters in 2018. The fight to expand the Convention Center has been ongoing for years, so statements about the necessity and importance of an expansion are worth a closer look. Asking voters to greenlight a Convention Center expansion in 2017 is all but dead, but it’s a safe bet it will return, just as it did after previous attempts fell short.

An expansion to the center would surely allow more events to be held, and data exists showing some event planners find the current space too small to meet their needs, and that some events can’t be accommodated due to other event reservations. But just how many events have been lost to space and date constraints?

“Lost 1,000 conventions & events in last two years,” said a tweet sent out from Faulconer’s Twitter account in the run-up to Monday’s special election vote. The claim was in a graphic that aimed to capture what’s been lost due to the city’s failure to expand the convention center.

The data point was sourced to a recent report by Chicago firm HVS Convention, Sports & Entertainment Facilities Consulting. The report was commissioned by the San Diego Tourism Marketing District and cost $43,450, according to a consultant for the district, which uses hotel tax money to promote local tourism and events.

A look at the HVS report, though, immediately puts some big holes in the mayor’s claim.

First, the data appears to come from a chart showing lost events for the last four years.

Above that chart is a disclaimer that says some event planners reserved dates in multiple years knowing they would ultimately only book one. “Consequently, there is some double counting in the lost business data,” the report says.

Below the chart is another disclaimer: “Over the past four years, the SDCC has lost an average of 527 events and 2.75 million room nights. These events are lost for a variety of reasons. Nearly 58% of them are lost due to date and space conflicts at the SDCC.”

So, on its face, events lost to date and space conflicts — something an expansion could ostensibly address — total only 58 percent of the events shown in the chart, and some of those results might be double-counted. Fifty-eight percent of the 1,171 events reportedly lost in 2015 and 2016 would be 679. That’s a lot less than 1,000.

A closer look at the source data also casts doubt on the mayor’s 1,000 events lost claim.

Voice of San Diego obtained lost booking data from both the San Diego Tourism Authority and San Diego Convention Center this week. The authority handles long-term bookings, those for events more than 18 months away, and the convention center reserves events less than 18 months away.

The Tourism Authority reported a total of 309 long-term bookings were lost in 2015 and 2016 to date and space issues. Data produced by the San Diego Convention Center shows 366 short-term bookings were lost due to date and space conflicts in the same two-year period.

Add them together and you get a total of 675 events lost in two years, almost the same number as the estimate from the HVS chart, and again not 1,000.

Elsewhere in the HVS study, annual event losses due to space and date issues are reported at 284. Some questions about that figure emailed to HVS’s managing director Thomas Hazinski this week have not been answered.

The mayor’s tweet seemed to imply the center expansion could recapture 500 events a year.

Yet recent projections by HVS and other consulting firms in previous years have estimated far fewer events will be gained from an expansion.

HVS estimated the center could recover at least 52 events lost per year – about one-tenth of what Faulconer suggested.

A $90,000 study by Minneapolis-based Convention, Sports & Leisure International in 2015 projected a waterfront expansion could attract an additional 28 events.

And a 2009 report by AECOM projected an expansion could add 50 events.

Voice of San Diego asked the mayor’s staff for evidence supporting the claim 1,000 events were lost in the last two years due to the failed expansion.

Faulconer’s deputy chief of staff, Matt Awbrey, said a lack of convention space “is central” to convention, job and revenue losses. He also appeared to acknowledge the error.

“Thanks for bringing this up. The information out there should have been clearer and will be moving forward,” Awbrey wrote in an email. “It remains significant that the study found the convention center lost out on 1,000 events in two years and the majority of those events were lost due to a lack of space. We did not have the room to compete for these events, and we still don’t.”

The mayor’s claim the city lost 1,000 events in the last two years for failing to expand the convention center is not accurate, and existing data shows the number is likely closer to 675 or 680. Further, an expansion is not expected to recapture all those lost events.

For all these reasons, we find the mayor’s claim is false.