There’s little hard information to stand up or knock down criticisms like those, in part because the program’s scant data collection makes it all but impossible to weigh the program’s local benefits against its long-term costs to taxpayers.

For example, companies in opportunity zones aren’t required to disclose whether they're claiming the tax break. Those that do tap the benefit aren’t obligated to create new positions or document any job creation, as many previous development programs demanded.

The lack of transparency extended to how zones were selected. State officials, who were asked to pick impoverished census tracts for inclusion in the federal program, weren’t required to seek public input before making their choices. Loose selection standards allowed state and local officials in some areas to dole out the federal breaks based on political favoritism rather than economic need, according to a Duke law school study, which didn't examine the billionaires' tracts.

The three billionaires and their companies didn't address questions from Bloomberg News about whether they asked state officials for the designation for their territories or whether they intended to use the break; Bezos’s Blue Origin declined to comment for this article and officials for SpaceX didn’t respond to requests for comment.

“We have been members of our communities in California for over a decade and in New Mexico for almost a decade. We have not taken advantage of opportunity zone tax incentives,” said a Virgin Galactic spokeswoman. The company didn't comment on whether it intended to use the break for any future profits.

State and local officials in these areas see not only new jobs but also intangibles, like optimism, that a backyard moonshot project can generate. They said they based their opportunity zone selections on the economic need of the communities. Because the billionaires’ companies have the potential to create hundreds of new jobs, local community leaders said they welcomed any federal incentives that might encourage that growth. Musk’s SpaceX launch site in Texas, for example, has brought 500 jobs to the region since 2014, according to a local space development official, although it couldn't be determined whether any of them can be attributed to the recent opportunity zone breaks.

It’s unclear whether President-elect Joe Biden will bring radical changes to the effort. One of his close economic advisers, Jared Bernstein, supports the program and co-wrote the research paper upon which it is based. Biden has pledged to continue it while requiring investors to show the projects benefit the community.

The program’s opacity frustrates even supporters such as Senator Angus King, an independent from Maine who caucuses with Democrats.

“This is taxpayer money,” said King, who has co-sponsored a bill to mandate more disclosure from companies and funds that invest in the zones. “Taxpayers have the right to know who is using it, how much it’s going to cost, and whether the project being subsidized will add economic activity to the community, like it’s supposed to.”

There’s no dispute that Musk is spurring economic activity around Boca Chica Village, a settlement at Texas’s southernmost edge. What’s less clear is how much new opportunity the program is creating for residents.