In the aftermath of damage caused by Hurricanes Irma and Maria, prominent officials and private sector players have floated various figures approximating the price tag of the Virgin Islands’ recovery, though little evidence has been provided to back up these numbers.

“If we look across Dominica, Barbuda, Turks and Caicos, British Virgin Islands, Anguilla — the islands and territories affected worst — I have no problem going out on a limb and saying that’s a $1 billion project over time in each of those islands,” Stephen O’Malley, the United Nations resident coordinator for Barbados and the Organisation of Eastern Caribbean States, said in a press conference Tuesday.

Mr. O’Malley — noting that they hadn’t yet secured exact figures — did not clarify whether that $1 billion number applied to each of the badly hit islands in the VI or the territory as a whole. He later re-estimated the recovery cost as $0.5-$1 billion.

The UN official could not immediately be reached for comment.

Should Mr. O’Malley’s estimate apply to each of the major islands in the VI, his guess would be significantly closer to some of the homegrown numbers being tossed around here.

“A conservative estimate for the restoration of the British Virgin Islands to pre-Irma economic growth is $4 billion,” wrote Lorna Smith, interim director of BVI Finance Limited, in a letter circulated to the financial services community.

Ms. Smith also said it would cost government $48 million to restore power throughout the territory by the end of December, though she provided no citation for either estimation.

Ms. Smith could not immediately be reached for comment.

Last month, Sir Richard Branson provided a similar estimate to CNN, saying that the cost of rebuilding the VI would be $3-4 billion. He didn’t say how he arrived at those numbers.

The science of cost

Adam Smith, a physical scientist at the United States’ National Oceanic and Atmospheric Administration, recently broke down the elements of how the official price tag of a natural disaster is assessed.

In an interview with ResearchGate, an academic social media site, Mr. Smith said the figure includes physical damage to residential, commercial, and public buildings; damage to material assets within buildings; time element losses like businesses interruptions; and damage to vehicles, boats, offshore energy platforms, public infrastructure, and agricultural assets.

“However, these loss assessments do not take into account losses to natural capital/assets, health care-related losses, or values associated with loss of life,” he told ResearchGate. “Therefore, the estimates should be considered conservative with respect to what is truly lost but cannot be completely measured.”

The loss estimates are calculated using input from insurance companies and government agencies and must take into account damage to uninsured or underinsured assets, the scientist explained.