Colorado’s tax collections from recreational marijuana sales in the past fiscal year came in more than 60 percent below early predictions, and now a state lawmaker says it may be time to reconsider the tax formula.

State Rep. Dan Pabon, who is leading a special legislative committee on marijuana revenue, said the medical-marijuana system also may come under scrutiny.

“There’s some real impact that the medical marijuana market is having on the recreational marijuana market,” said Pabon, D-Denver. “I think it’s worth looking at the taxation on the recreational side but also looking at the rules and regulations on the medical side.”

Tuesday marked the first meeting of the committee, which is studying how Colorado spends its marijuana tax money.

The first item of business: Why is there so much less of it than predicted?

When Colorado voters approved special taxes on recreational marijuana in November, the official fiscal analysis estimated the taxes would bring in a combined $33.5 million through that fiscal year, which ended this summer. Budgeters for Gov. John Hickenlooper had similarly optimistic projections.

But the actual number came in at just more than $12 million.

A market study for the Colorado Department of Revenue says the lower-taxed medical-marijuana market, which continues to outpace the recreational market in sales, is to blame.

Rather than pulling consumers out of the medical-marijuana market, the recreational market largely has feasted on tourists and people who previously bought pot on the black market.

“I think our original assumption about the cannibalization was wrong,” Colorado Legislative Council economist Larson Silbaugh said at Tuesday’s committee meeting.

The result, suggested David Blake of the Colorado attorney general’s office, is that the resilience of the medical-marijuana market “is being driven by avoidance of that tax.”

Dorinda Floyd, the chief financial officer for the Department of Revenue, said recreational sales continue to rise and eventually are expected to surpass medical sales “in the out years.”

Meanwhile, state economists have adjusted their predictions. A forecast in June significantly dialed back expectations for the current fiscal year — $30.6 million in special recreational marijuana taxes, compared with the roughly $100 million that Hickenlooper’s office had predicted this year.

A new forecast is due in September.

“While I think our forecasts are getting better,” Silbaugh said, “they’re still based on just six months of data.”

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/johningold