"I would expect labor regulations in a Romney administration to be more friendly to management and less friendly to organized labor," for issues such as the prevailing wage for companies hiring seasonal foreign workers through the H-2A and H-2B visa programs, he said.
But Bronars added that Congress and the National Labor Relations Board play a role in labor, "so it's unwise to put too much emphasis on the president's role in this area."
Bronars added that Siegel's comments are at odds with data from the past two years with a fall in layoffs in 2011 and 2012.
"Companies are hiring fewer workers than before the recession but downsizing has often occurred through attrition -- and not replacing workers who retired or quit -- since 2011," he said. "So I find it unlikely that we will see a big increase in layoffs in 2013 whoever is elected president. A more likely concern is that hiring continues at a slow pace and we experience stagnation in growth rather than a wave of mass layoffs."
Harry Holzer, public policy professor at Georgetown University, said he was "very skeptical" about CEOs' claims that one candidate will directly affect a company's business practices.
"We don't even know, if Barack Obama is re-elected, what policies will come forth because he will have to negotiate with Congress," Holzer said.
Holzer said Siegel's email may have been inappropriate in a corporate setting. He said other business leaders have expressed direct support of a candidate, such as former Costco CEO Jim Sinegal speaking at the Democratic National Convention and former General Electric CEO Jack Welch expressing support for Mitt Romney.
"They might let it be known that they have preferences but that goes differently than pushing their employees," Holzer said.
"No one knows how the whole fiscal cliff will be resolved," he said. "Right now, the uncertainty is bad for business. Almost any resolution would be preferable to the current stalemate."