In making his first RBA board appointments, Treasurer Wayne Swan said he was creating "a very good blend of experience and renewal". The new board members are Catherine Tanna and John Edwards. They replace former Telstra chairman Donald McGauchie and leading economist Professor Warwick McKibbin. Both appointments were a surprise. Together with the replacement of Treasury secretary Ken Henry with his successor, Martin Parkinson, they represent a major remaking of the Reserve Bank of Australia's board.Notably, the changes leave the board without a noted economist for the first time in more than a third of a century. In succession, Professors Trevor Swan, Bob Gregory, Adrian Pagan and McKibbin have filled that role since 1975.Some analysts, such as Rismark's Christopher Joye, consider the outside economist's role vital. Such a board member probably has the best chance of exposing flaws in the arguments mounted to the board by RBA staff, who are among Australia's best economists. The role could have been filled by veteran economist Professor Ross Garnaut or an up-and-comer like Professor Mardi Dungey, a specialist in the effects of financial crises. Stephen Kirchner, of the University of Sydney, has suggested the RBA bring in a leading overseas economist.Even admirers of John Edwards would concede he is not in the top rank of pure economists. A mild-mannered ex-journalist turned economist, he is a narrator and public policy analyst rather than a theoretician. His strengths are his historical understanding and worldly experience.Edwards is best known for his stint as an economic adviser to Paul Keating, while Keating was treasurer and then prime minister, between 1991 and 1994. He then became HSBC Australia's chief economist - and also, quietly, a leading source of economic thinking for the Federal ALP during its time in Opposition. He took temporary leave from HSBC, in 2008, to work at the Treasury on the financial crisis. He has also written six books, including biographies of Keating and John Curtin, and is an adjunct professor at West Australia's Curtin University. For more of his economic thinking, see the following item.Catherine Tanna is much less well-known. A Queenslander and a lawyer by training, she was appointed in 2009 as head of global gas giant BG Group's Australian operations, and managing director of coal seam gas company QGC. She recently joined the Business Council of Australia and is well regarded in the business community but has no other board roles. She is a lifetime hydro-carbons executive, having previously worked at BHP Petroleum and Shell.Tanna was one of the few resource executives to support the Government in the row over taxes on profits last year. She called pre-election discussions with the Government over the tax "productive". In October, announcing the go-ahead for BG Group's Queensland Curtis LNG project, she declared her confidence that the new tax regime would "deliver sound and competitive economics" for the project.The RBA does not comment on appointments. But AAP reported yesterday that under a set of rules, made in December 2007 by the incoming Rudd government, "the Treasury