Robert Shiller, co-creator of the Case-Shiller home price index, said Friday that it’s a good time to buy a house, given today’s historically low interest rates, but he is less certain about the housing market’s overall strength.

Key uncertainties include the outcome of the euro zone crisis, Middle East unrest, Congress’ “fiscal cliff” budget negotiations and the new, speculative nature of the housing market itself, Shiller said in a Sun-Times interview prior to receiving the 2012 CME Group-MSRI Prize in Innovative Quantitative Applications at a ceremony at the W Hotel downtown.

“It’s very uncertain right now,” Shiller said of the residential housing market. “Speculative markets can surprise you.”

Chicago is set to benefit from a turnaround, since Shiller noted that the city didn’t suffer the degree of housing-price speculation as California or Florida.

Positive signs include a report Friday showing consumer sentiment in October rising to its highest level in five years and recent reports showing construction, home prices and home sales picking up while foreclosures decline, said Shiller, who is an economics professor at Yale University.

Yet Shiller’s research with economist Anne Thompson of McGraw-Hill Construction shows homebuyers as recently as June said they didn’t expect their homes to appreciate significantly in value for the next decade — a low expectation that has been on the decline for eight years.

Shiller also credited the federal government with helping boost the housing market. He believes there should be federal subsidies for professional financial counselors who sign an oath to work on their clients’ behalf, rather than sell products in their own interests, to help people understand risk management and the risks involved in home buying. The idea is among many innovations he suggests in his new book, “Finance and the Good Society.”

Shiller’s award is given jointly by CME Group and the Mathematical Sciences Research Institute. CME, which owns the Chicago Mercantile Exchange and the Chicago Board of Trade, maintains futures markets based on the Standard & Poor’s/Case Shiller Home Price indices.