Martin says it's overly simplistic for Mulcair to blame Canada's prosperous oilsands for artificially elevating the dollar and hurting manufacturing exports.
"To simplify what is a really important issue like that really does nobody a service," Martin told reporters Monday.
The 74-year-old former Liberal party leader was in Edmonton to receive an honorary doctorate of laws from the University of Alberta.
Mulcair has been sharply criticized in recent weeks by western premiers, including Alberta's Alison Redford, for saying that Canada is afflicted with the so-called "Dutch disease" phenomenon.
The theory is that the roaring oilsands economy is pumping up the dollar, making manufacturing exports from central Canada less attractive and thereby driving away business.
The premiers have called the remarks divisive and ill-informed. Martin — a former federal finance minister — agreed.
"The reason our dollar is high is we have a good balance sheet, and we want that," he said.
He said the ebbs and flows of finances depend on a number of intertwined factors and can't be blamed on any one industry.
Another ex-prime minister, Brian Mulroney, has also taken a run at Mulcair. He recently called the remarks divisive and unworthy of a man who aspires to govern from coast to coast to coast.
Mulcair has already taken steps to mend fences with the West, making a trip to the oilsands two weeks ago.
Martin was also asked Monday about a recent poll suggesting many in his Liberal party would like to merge with the NDP to present a winnable alternative to Prime Minister Stephen Harper's Conservatives.
Martin wouldn't comment on the issue directly, but said the Liberals are the only party to offer both fiscal competency and a social conscience.
"You've got to be faithful to your philosophy," he said.
"If your philosophy is in order to have a strong country you have got to have both a good balance sheet and strong social programs, (then) we are the only political party that advocates that.
"We are not a party of the extremes of either the right or the left, and I think that that's what Canadians ultimately will be looking for."
Martin declined to weigh in on a pending decision from the party executive on whether to allow interim leader Bob Rae to run for the job on a permanent basis.
When Rae was handed the interim job in May 2011, he pledged not to run for the permanent post, a move that would give him a head-start on his opponents.
Martin said it's out of his hands.
"There is an executive and the executive will deal with that issue."
Martin was at the helm as prime minister for a tumultuous two years that ended in January 2006, when Harper's Conservatives defeated his minority Liberal government in a general election.
Martin's administration was undone by the ongoing sponsorship scandal, which saw cash earmarked for federal programs directed instead to party friends and functionaries.
Prior to being Canada's 21st prime minister, the former Montreal-area MP won international accolades as finance minister under then-premier Jean Chretien.
Under Martin, Canada reduced its chronic fiscal deficit and cut its debt-to-GDP ratio while making strides in pension reform.
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