In theory, the state auditor’s job is to check the books of public agencies. In practice, the office can play a broader role as an in-house watchdog, promoting effective government by highlighting redundancy, giveaway contracts, and other forms of inefficiency. The retirement of longtime incumbent Joseph DeNucci has attracted a bumper crop of candidates who see new possibilities in the auditor’s position, and voters can take comfort in the spirited contests for both parties’ nominations.

DeNucci is well-liked in state government. Yet his decision this summer to grant a retroactive 5 percent pay increase to his staff on his way out the door was precisely the sort of abuse that an auditor should try to root out, especially in difficult economic times. Voters should seek a successor who is committed to a government that works well — and operates for the benefit of its citizens rather than for special interests.

In a sign that she grasps the potential of the position, former Turnpike Authority board member Mary Z. Connaughton describes the state auditor’s job as the second-most important one in state government. Connaughton, a Republican, is highly qualified for the post, based on her experience as a certified public accountant and in a variety of government offices.

Many readers will remember Connaughton most for the dissenting votes she cast against Governor Deval Patrick’s priorities as an appointee of former Governor Mitt Romney on the Massachusetts Turnpike Authority board. While some of her stances were exasperating to fellow board members, she showed a deep knowledge of and interest in the details of the authority’s finances. Connaughton has also served as chief financial officer of the state Lottery and as an accounting professor at Framingham State.

Connaughton’s primary opponent is Kamal Jain, a genial Libertarian-turned-Republican who has intriguing ideas about using technology to promote greater public scrutiny. But Connaughton’s qualifications and her experience in public agencies put her in a better position to use the auditor’s office to encourage transparency in state government.

Of the three candidates for the Democratic nomination for auditor, former state labor secretary Suzanne Bump is best positioned to look out for the interest of citizens. She argues that, as a believer in the power of government to improve people’s lives, she feels an obligation to make sure it runs well.

Bump has a clearer fix than her opponents on how the auditor’s office might be used for the public good. She promises to zero in on the state’s Medicaid program, MassHealth, as a way of ensuring that parties involved in health care reform are doing their jobs at maximum efficiency; it’s a shrewd allocation of resources, a cardinal example of where a state auditor can do the most good.

Guy Glodis, currently the Worcester County sheriff, promises to promote economic development, but some of his proposals — such as investigating the use of out-of-state labor on local projects — lie at some distance from the essential duties of the auditor. Mike Lake, a whiz kid who worked at the White House at the end of the Clinton administration, seems genuinely interested in holding public agencies accountable, but his lack of experience at the state or local level could hamper his ability to carry out the nuts-and-bolts aspects of the job.

In a state dominated by Democratic elected officials, the Democratic nominee for auditor has a special burden to demonstrate independence from the party’s establishment and its most powerful constituencies. Perhaps because she has DeNucci’s support, Bump appears loath to criticize the raises he ordered. Still, she’s displayed significant spine in other ways. As a state legislator, Bump earned the ire of trial lawyers, and lost her seat to a primary challenger, in part because of her efforts to bring down out-of-control worker-compensation costs.

Her Democratic opponents for auditor also tout their independence: Lake has the best claim to outsider status, and Glodis won his current job by challenging an incumbent. But Bump has a clear edge. She’s committed to finding ways to improve government — and knowledgeable enough about government to know where to look.