ALBANY — Experts in government finance say most state and local governments can expect at least another two years of revenue shortfalls, and that this recession is certain to be worse than the last one.

“It’s kind of like getting hit by Katrina II,” said Donald Boyd, a senior fellow at The Nelson Rockefeller Institute of Government in Albany. “This is probably going to be worse in many respects than the last time, even though the last was the worst in at least half a century. This one will be broader, hitting more states than the last one did.”

According to preliminary data from 42 states, state tax collections continued falling in the third quarter, institute officials said Thursday at a public policy forum. Revenue was essentially flat, rising 0.1 percent over the same quarter last year.

States that have a greater dependence on taxing higher-income salaries will take the biggest hits, Boyd said.

“It’s a dangerous thing,” he said. “With progressive taxes, especially in a state like New York and some other states — especially California — you will be subject to absolutely wild revenue swings, and unless you have a way to deal with those wild revenue swings, you are in trouble.”

“It’s extremely good in the good times, but you get hammered in the bad times,” Boyd said.

Different states had different challenges. Boyd broke those down in three categories. Some were hit early and hard by the housing crisis, including Arizona, Nevada, California, Florida, Michigan and Rhode Island.

A second group has been doing well thanks to natural resources, but he said that could change. Those are states like Texas, Oklahoma, Alaska and Wyoming.

A third group gets much of its income tax revenue from either financial markets or the financial services industry. As that declines, so will revenues in places like California, New York, Colorado and Massachusetts.

State and local governments also face one challenge that the federal government doesn’t: They have to balance their budgets.

“As the federal government is planning to spend more, state governments are having to cut,” he said.

Meanwhile, New York Comptroller Thomas DiNapoli said the ability of local governments to borrow has been hampered by the global credit crunch.

In a report issued Thursday, DiNapoli said higher borrowing costs are “squeezing local governments” and could have “serious implications” for school districts and municipalities that need short-term credit to manage cash flow and finance projects.

The current economic downturn in many ways mirrors the downturn in the early 2000s. In both instances, the country has seen a huge economic boom, followed by a huge decline in capital gains. Capital gains are the difference between how much is paid for an investment and how much is received when it’s sold. The current downturn and the one earlier this decade also were preceded by a boom in wages in the financial services sector.

In New York, the financial sector accounted for about 6 percent of employment and 41 percent of all New York wage growth since 2003. New York gets 60 percent of its tax revenue from personal income tax.

Sales tax is also down for most states, declining 1.9 percent in the third quarter compared to the same period last year — the largest decline in 17 years.

It’s unclear how state and local governments can prepare and survive these financial crises. Boyd recommended that state and local governments build up their reserves and control spending, but in most cases statutes limit how much of a rainy day fund can be built.

“What you hope is that all this analysis would lead to some changes in public policy, but I’m not sure it would,” said Henry Wulf, a senior fellow at the Rockefeller Institute.