Lobbying state lawmakers and government officials cost businesses, unions and issue-advocacy groups at least $715 million last year, with nearly half the money spent in California, New York and Massachusetts, a new report found.

The study by the Center for Public Integrity (search) also concluded that many state laws did a poor job of letting the public know the details of lobbyists' spending on lawmakers, and what issues were discussed.

"You've got so many part-time legislators, and they're relying on lobbyists," said Bill Allison, the center's managing editor. "There are often millions of dollars or billions of dollars at stake, and the interests that want to share in that wealth definitely spend the money to protect their interests."

"But the public's interests often don't get heard."

The study examined disclosure reports by lobbyists or the companies that hired them in 39 states where such information is available. It ranked the states on that information, including how much is required from lobbyists and what states made public.

The study found that $715.9 million was spent by 34,000 principals - meaning businesses, trade associations, labor unions and issue-advocacy groups. They hired 42,000 individuals to lobby legislators and other state elected officials, which breaks down to nearly six lobbyists and $126,000 devoted to each legislator in those 39 states.

Much of that money - $342.9 million - was spent in California ($197.2 million), New York ($92 million) and Massachusetts ($53.7 million).

Legislators and lobbyists said that the money spent reflects an important part of the way government works - the dialogue between legislators and those affected by laws.

"Lobbyists provide information. Yes, they ask you if you will please support a piece of legislation," said Connecticut state Rep. Brian Flaherty.

"At the end of the day, the legislator walks out onto that floor and - the way they're supposed to do it - makes a decision on their own to represent the people who elected them."

Connie Campanella, president of Stateside Associates (search), a government affairs group that hires state lobbyists across the country, says the system works the way it should. "I don't want a government sitting in a closet in the dark," she said.

She and Flaherty emphasized that lobbyists represent not just businesses but nonprofit groups, trade associations and health care consumers.

Each year, more states approve lobbying disclosure laws, with the total jumping from 18 in 1995 to 39 this year, the center said. The amount spent on lobbying is rising, too.

In 2000, the 34 states which then had reporting laws said a total of $565 million was spent; those same 34 states reported $667.6 million spent last year.

The study found a wide variation among states on how they regulate lobbyists.

Wisconsin and Montana don't require lobbyists to file reports documenting their spending, though it does require reporting by the companies that hire them. Many states ban gifts from lobbyists to public officials, though others allow for campaign contributions.

Pennsylvania's lobbying disclosure rules were struck down by the courts, and a new system has not yet been passed into law.

The report found that Washington state had the strongest reporting system, because it requires lobbyists to itemize all expenses in detail, file reports every month, and makes all the information easily accessible.

The study considered seven states "satisfactory" for their reporting requirements - Washington state, Kentucky, South Carolina, Connecticut, New York, Wisconsin and California.

It concluded that Wyoming was the worst, because reports are filed only once a year, and lobbyists aren't required to total spending by category or indicate what was spent on the household members of public officials.