This is one of the biggest supposed selling points of spending $300 million on warehouses, and yet apparently none of the proponents can agree on what one third of a billion dollars buys taxpayers.

From Wednesday’s Patch, which seems to be a very pro-”Aerotropolis” publication (emphasis added):

Mike Leblanc, co-chair of the Northwest Chamber’s economic development committee, said if the legislature waits until September to look at the issue, the Chinese may discover Kansas City, MO or Memphis, TN are more serious than St. Louis about establishing a partnership.

Leblanc said establishing the China Hub would create 5,000 jobs in the St. Louis area. He wondered how the legislature would leave the 2011 session without addressing the issue.

“To leave session without addressing this issue and the possible creation of 5,000 jobs is unacceptable to most of the voters in a nonpartisan way,” Leblanc said.

“Possible creation.”

Then, from Thursday’s St. Louis American, which also seems to be a very pro-Aerotropolis publication (emphasis added):

On May 13, the last day of Missouri’s 2011 legislative session, the so-called “Aerotropolis” proposal died when legislators couldn’t resolve their differences on tax credit reforms to a larger economic development bill. Aerotropolis had been bundled as part of that development package.

Advocates of Aerotropolis claim its tax incentives would spur the creation of 23,000 construction jobs and 13,800 new permanent full-time jobs.

It appears that the St. Louis American’s numbers originate from a St. Louis Regional Chamber & Growth Association (RCGA) study dated April 19, claiming 23,325 construction jobs and 13,844 full-time “operations” jobs would result from the project, or 37,169 jobs total.

Two Saint Louis chambers of commerce, two radically different answers for the job impact of Aerotropolis, one 700 percent greater than the other.

The RCGA on Friday produced even more recent numbers than those cited by the American, in response to Michael Webber’s piece in Air Cargo News. The difference? The newer analysis, apparently dated April 27, now says that the project will lead to 18,468 construction jobs and 10,941 full-time “operations” jobs, or roughly 29,000 jobs, a reduction of more than 20 percent from the original numbers.

So, now we have three figures for the number of jobs promised, two of them originating from the RCGA.

Perhaps worse? The RCGA repeated their larger April 19 job numbers in their May 2 Monday briefing, after they apparently had new jobs numbers to distribute. Before it released these April 27 numbers to Air Cargo News, had the RCGA made these downwardly revised numbers available to the public? We know that the St. Louis American certainly relied on long-outdated information.

More importantly, are supporters just making up these jobs figures as they go along? None of the proponents seem to be able to keep their job numbers straight.