When it comes to making decisions about the public purse, appearances matter. Taxpayers need to have full confidence that their money is being fairly spent by those elected to handle government budgets.

That’s why most states and local governments have policies on conflict of interest, ethics and disclosure. But a recent local example illustrates why policies governing Minnesota public officials need revision, most specifically on possible conflicts involving spouses.

Last month, the Star Tribune reported that veteran Hennepin County Commissioner Peter McLaughlin voted on several multimillion-dollar trash disposal agreements with a company that employs the law firm where his wife works, but that he was not required to disclose the connection.

The contracts are with Great River Energy, the firm that operates the Elk River processing plant where the county sends its garbage to be converted into electricity. Great River hired McLaughlin’s wife, Nancy Hylden, and her law firm colleague Richard Forschler, in 2009.

In fact, Hylden prominently lists her work with Great River in her bio on the website of the law firm, Faegre Baker Daniels.

(Hylden also has been a registered lobbyist for the Star Tribune.)

Hylden said she gave “strategic counsel’’ to Great River in the past but hasn’t worked directly for the company in years, though she continues to be registered as a lobbyist for the firm. Her coworkers met with county commissioners, including McLaughlin, to represent Great River’s interests.

For his part, McLaughlin says Hylden’s lobbying work on behalf of Great River had no influence on his decisions. He emphasized that his negotiations with the company over the years have saved taxpayers millions of dollars.

The five-term county commissioner told an editorial writer that his board colleagues knew where his wife worked and that it was not necessary — or legally required — to disclose the connection any further.

McLaughlin said the county is a $2 billion operation with hundreds of contracts. His wife is a partner with one of the largest law firms in the state, with hundreds of attorneys who lobby on lots of issues, so it would be impossible to keep track of all the possible connections, he said.

Ethics experts agree that there’s no evidence that McLaughlin broke any laws. But they also say state and local disclosure requirements should be modified to make government more transparent.

Minnesota law says that public officials acting on matters that would “substantially affect the official’s financial interests or those of an associated business” must submit a written statement describing the nature of the potential conflict to a superior. But the regulations do not address spouses.

Gary Goldsmith, executive director of the Minnesota Campaign Finance and Public Disclosure Board, called the statute “weak’’ and said that a proposed bill to make it stronger and include spouses and children went nowhere during the 2013 legislative session.

State lawmakers should look south for guidance. A Texas law covering state legislators requires disclosure when the member’s spouse is a lobbyist on an issue that he or she is introducing, sponsoring or voting on. And it calls for more information from lobbyists. That’s another area where Minnesota law is lacking. Lobbyists here are required to register client names, but don’t have to disclose who they lobby or what they lobby for.

That was one of the reasons why the Washington, D.C.-based Center for Public Integrity gave Minnesota an “F” grade on its lobbying disclosure requirements.

McLaughlin found himself at the center of a controversy because of the appearance of conflict. He, and other public officials in Minnesota, should welcome fuller disclosure of relationships that might raise questions in the minds of the taxpayers they represent.