Warren Buffett and Berkshire Hathaway recently announced a share buy-back authorization, which may be signaling optimism from Buffett on the economy.

The move marks the first time in four decades that Berkshire will be authorized to buy back its own shares, according to Bloomberg. It is allowed to do so only if its price is no more than 10% above book value. Berkshire’s willingness to repurchase shares is a bullish sign, according to Mark Luschini, chief investment strategist at Janney Montgomery Scott LLC. He told Bloomberg that the announcement “is a bit out of character and for that reason is seen as very constructive both in terms what [Buffett] sees as an opportunity to buy a great asset, namely Berkshire stock, trading at a discount to historical book value as well as the portfolio of companies within Berkshire that he thinks is undervalued.”

Others contend that the move may be a sign that Buffett isn’t finding enough values in the stock market, and thus would rather buy back Berkshire’s own shares. But fund manager Eric Green of Penn Capital management seems to disagree. He points out to Bloomberg that Buffett “has a lot of investments in the largest companies in the market, so putting his money in Berkshire is another way of being bullish on the market. If the stock market is going down, then his stock will go down, and he’s certainly smart enough to know that and he thinks the market is undervalued.”

CNBC’s Alex Crippen, who maintains the Warren Buffett Watch blog, says, meanwhile, that the fact that Berkshire is authorizing the repurchase of shares at a premium of up to 10% of book value seems to be somewhat of a diversion from Buffett’s past comments. “In his letter to shareholders earlier this year, Buffett called book value an ‘understated proxy for intrinsic value.’  That is, book value would generally be below intrinsic value,” Crippen says. “But back in May of 2009, he told shareholders Berkshire’s stock price would have to be ‘demonstrably below’ a conservative estimate of the company’s intrinsic value for a buyback to be considered.  He was setting a high bar, because he generally prefers to use cash for acquisitions or investments.”

Crippen also notes that the move involves an authorization to buy back shares — not a mandate. “Berkshire isn’t necessarily buying back shares now, and may never repurchase any at all,” he says. “By saying it might, however, Berkshire could be trying to suggest a ‘floor’ for the company’s shares.”

Buffett, for the record, has so far been mum on the move.