Nassau County Executive Edward Mangano with Suffolk County Executive Steve...

Nassau County Executive Edward Mangano with Suffolk County Executive Steve Bellone at an LIA breakfast in Woodbury on Jan. 5, 2016. Credit: Howard Schnapp

“Risky Business” and “Trading Places” were two movies released in the summer of 1983. But Nassau and Suffolk counties seem to be channeling the films — or at least their titles — as analyses of their proposed 2018 budgets.

“Risky Business?”

That goes for both counties.

For Suffolk, an assessment by the county’s independent office of budget review found that the $3.05 billion budget proposed by County Executive Steve Bellone overestimates sales tax revenues, underestimates police department pay and relies on — yes — “risky” assumptions that could widen the structural deficit.

In Nassau, the county’s financial control board also branded some revenue assumptions in County Executive Edward Mangano’s proposed plan as risky, including $60 million in county fee increases that lawmakers are unlikely to approve before Election Day.

As for “Trading Places?”

Looks like Suffolk is projected to have a 2018 structural deficit larger than that estimated for Nassau, where the Nassau Interim Finance Authority has overseen county budgets for 17 years — six of them as a control board with the authority to reject budgets.

Suffolk and Nassau seem to be trading places in other areas, too.

The 31-page NIFA report on Mangano’s budget included some praise. For instance, the authority noted that Nassau had “realigned its finances” and whittled away its structural deficit, which reached a high of $182 million in 2014.

The Office of Budget Review’s 200-page report for Suffolk, meanwhile, started its introductory section with a quote: “Ask yourself if what you’re doing today is getting you closer to where you want to be tomorrow.”

One issue for both counties is sales tax proceeds, which account for the largest source of revenue — yes, larger than the county portion of the property tax.

In Suffolk, sales tax revenue estimates for 2018 are too high, analysts said.

In Nassau, estimates are conservative, according to NIFA, although not conservative enough.

Risky savings assumptions in Suffolk include tens of millions of dollars in concessions from public employee unions, because contracts haven’t yet been negotiated. The BRO report also questioned the county’s plan to pull in revenue through borrowing, including dipping into the sewer Assessment Stabilization n fund.

NIFA complained about similar tactics. It noted that Nassau’s intention to borrow from a reserve fund in 2018 would do little to bring down its deficit. NIFA also said it didn’t buy the county’s assertion that increases in pay for union employees would be cost-neutral because of savings elsewhere.

We could go on. But the bottom line — from two independent assessments — is that Nassau, with a control board, still is having the kinds of troubles that Suffolk now is facing.

Which, politically and governmentally, makes fixing finances on Long Island risky business indeed.