An update with a response from Walmart, appears below.

In an interview with Bloomberg Businessweek, a top Walmart official said the company has evaded unionization in part by reminding workers what benefits “might go away” if they organized.

Interviewed for this week’s Businessweek cover story on the current labor campaign facing the company, Walmart Vice President of Communications David Tovar told reporter Susan Berfield, “We have human resources teams all over the country who are available to talk to associates, and we will get questions about joining a union. We would say, ‘Let us remind you of all that Walmart offers, and of what might go away. Quarterly bonuses might go away, vacation time might go away.’ ”

The article did not make clear when, where, or how frequently Tovar said such comments were made. Walmart did not immediately respond to a mid-afternoon request for comment regarding the meaning or context of Tovar’s statement.

Labor leaders and allies have long complained that US law fails to restrain companies from threatening workers who seek a union, for two reasons: First, because even explicit threats to punish workers for organizing generally bring only minor penalties. And second, because employers can intimidate workers through implied threats—phrased as predictions—without breaking the law. In a 2009 analysis, Cornell Director of Labor Education and Research Kate Bronfenbrenner found that employers “threatened cuts in benefits or wages” in 47 percent of union election campaigns between 1999 to 2003, and made “threats of plant closing” in 57 percent. (Bronfenbrenner’s paper was published by the Economic Policy Institute and American Rights at Work.)

Asked about the HR statements Tovar described to Businessweek, former NLRB attorney Jeff Hirsch e-mailed, “These types of comments (and worse) are extremely common and effective.” Hirsch, now a law professor at the University of North Carolina, added that such comments are often made in mandatory on-the-clock “captive audience” meetings, and that even if they’re not stated as explicit threats to punish workers for organizing, “employees of course know what’s being said.”

Are the conversations Tovar is describing HR staff having with workers illegal? That would depend on whether, under the law, they constitute predictions or threats—employers generally have the right to “predict” dire consequences from unionization, but not to “threaten” them. Hirsch said that, absent context, the kind of comment Tovar recounted is “probably legal because it’s pretty wishy-washy,” though the NLRB to find differently if it were accompanied by other anti-union activities.

Lance Compa, a labor law professor at Cornell, said that the comments to workers described by Tovar “might well constitute” a violation of labor law, depending on the context. “Just changing ‘will go away’ to ‘might go away,’ ” e-mailed Compa, “does not automatically cure a possible violation of the NLRA if employees might reasonably conclude that they could be punished by losing these benefits for supporting a union.”

“To be safe,” added Compa, “management normally has to couch the possible loss of benefits in a discussion about collective bargaining, saying that bargaining is a two way street, wages and benefits are negotiable, management has the right to bargain hard, you might lose some benefits, you might gain some benefits, maybe nothing will change except you’ll be paying dues, and so on.”

Last month, the union-backed retail workers’ group OUR Walmart filed an NLRB charge that cited a different statement Tovar made to the media as an alleged illegal threat: his comment that if workers didn’t show up to work on Black Friday, “depending on the circumstances, there could be consequences.”

Update (7:40 PM, 12/17/12): In a Monday evening e-mail, Walmart spokesperson Dan Fogleman said that Tovar's quotes "as published" lack "additional context." Fogleman wrote, "David's comments were intended to illustrate that there are no guarantees in the collective bargaining process. Everything is on the table and subject to negotiation, up or down, by both sides. We believe that is an important fact for our associates to know, especially given that Walmart's pay and benefits package typically meet or exceed those at a majority of our competitors, including those that are unionized." Fogleman's e-mail did not address how frequently, or in what setting, Walmart communicates this message. 

It was the fear of losing their jobs that kept most low-income workers from striking. Check out Nona Willis Aronowitz's coverage here.