A two-person board committee? They exist—even at some of America’s biggest companies. The committees that figure out the pay for top executives at Yahoo Inc.% and Alphabet Inc., the parent of Google, have only two board members. That’s also true for the committees that recommend new directors for Chipotle Mexican Grill Inc.% A two-member committee “is out of step with how other boards operate,’’ says Michelle Edkins, global head of corporate governance and responsible investment for BlackRock Inc.,% a giant money manager. Governance experts contend very small committees lack different perspectives and may stall due to a tie vote or absent member. There were 11 companies in the S&P 500 index as of Dec. 9 where key board panels consist of just two people, according to a Wall Street Journal analysis of 2015 proxy statements and data from corporate filings service MyLogIQ. Along with the audit panel, the committees overseeing pay, prospective directors and corporate governance carry out the most complex assignments and are closely watched by institutional investors.

Corporate boards use committees to divide up the work so that members can dig more deeply into specific tasks, ranging from overseeing chief executive succession to financial reports, audits and internal controls. Their work and decisions then get shared and reviewed by the full board. Both Nasdaq and the New York Stock Exchange require companies to have audit committees of at least three board members, and Nasdaq listed firms must have a compensation committee with at least two people. On average, boards of S&P 500 businesses have at least four members on the compensation, governance and audit committees, according to research firm Equilar Inc. Some board committees are much larger. Thirteen of the board’s 15 people sit on the governance committee at Charles Schwab Corp.%Glass, Lewis & Co., the second-biggest U.S. proxy-advisory firm, has taken aim at companies with tiny audit panels. The firm, which advises institutional investors about how to vote their corporate ballots, will oppose the re-election of directors at businesses with fewer than three audit committee members.

Those firms ignore the stock exchanges’ rules for audit committees or aren’t listed on them. Inside America’s Boardrooms Third in a series on how business is done on corporate boards. Boards Get More Independent, but Ties Endure (1/19/2016) Three, Four, Five? How Many Board Seats Are Too Many? Data: How U.S. companies stack up in terms of board pay A panel that small “concentrates oversight on too few individuals (or just one), given the important financial and risk-oversight duties provided,’’ says Robert McCormick, chief policy officer of Glass Lewis. No company in the S&P 500 index has an audit committee with only two people, according to the Journal analysis. During the 2015 proxy season, the proxy adviser targeted board members over this issue at 31 companies, most of which have a small market capitalization. Only one such director failed to win majority support, but Glass Lewis had raised multiple objections to her re-election. Those companies that tap only two members for an important board panel generally say fewer participants allow the committees to function efficiently, and the results of their work must be approved by the full board.

The Chipotle board feels comfortable with a two-member nominating and governance committee because uninvolved directors frequently offer their ideas about its pending issues, says Chris Arnold, a spokesman for the burrito chain. “The committee can act expediently and efficiently when necessary.” Justice Department Gets More Time to Study Alaska Air, Virgin America Mergerionmax ion 390 hepa uv air purifier U.S. Oil-Rig Count Climbs by Twohunter air purifier 30748 review USG Names Jennifer Scanlon CEO-Electoreck dualmax air purifier (certified factory refurbished) 21st Century Fox Boosts Pay of Rupert Murdoch, Sons Similarly, staffing company Robert Half International Inc.%

has no plans to enlarge its two-person compensation committee. “The company believes small committees and boards are nimble and effective,’’ says Frederick “Rick” Richman, head of the pay panel and lead independent director. “It’s not about the number of people.” The company’s board has six people, compared with an average of 8.9 directors at Russell 3000 companies. Robert Half is “actively looking for an additional board member or two,’’ a spokeswoman says. Mr. Richman cites his committee’s knowledge about compensation programs that attract and retain key executives, access to independent pay consultants and use of external research. He joined the pay committee in fall 2008, while his 82-year-old colleague Andrew S. Berwick, Jr. has served on it since 1989. The committee had three members until 2010. What about the problems of reaching a quorum or breaking a tie? Mr. Richman says the compensation committee doesn’t meet unless both members can be present, and the entire board would settle a matter in the unlikely event of a tie.

In general, “the best board committees work well when there are three or more,’’ says Michael J. Wolf, co-founder of Activate Inc., a technology and strategic consulting firm, who served as a Yahoo director between May 2012 and July 2013. “You need to be able to have diverse points of view,’’ says Mr. Wolf, who isn’t currently on any public-company boards. At both Yahoo and Alphabet, the compensation and governance committees currently have two people apiece. The Yahoo pay panel consists of Chairman Maynard Webb Jr. and fellow director Jane Shaw. The two must tackle touchy issues such as stock awards, perquisites and severance for senior officers. In 2014, some investors criticized the company over the expensive firing of its No. 2 executive, Henrique de Castro, who got ousted after a little over a year on the job. Mr. de Castro collected about $58 million, the 2015 proxy said. Yahoo declined to comment. The board is currently evaluating selling its core Internet business.