City Controller Rachael Heisler urged the mayor not to count on that money in coming years. But Mr. Gainey’s revised revenue projections actually increased the amount of money the city expects to collect.

“Unfortunately, governments have a tendency to have rosy revenue projections and very conservative spending projections,” said Sheila Weinberg, founder and CEO of Truth in Accounting, a nonprofit that advocates for stricter financial practices in cities and states across the country. “Then, when they get into trouble, they have to use these one-time budgeting gimmicks to make everything work out.”

In other cities that have faced budget crises, leaders have papered over their problems with accounting maneuvers that masked the true scope of the trouble.