Picket lines, protesters and a crash course in labor relations provided this year’s back-to-school greeting for freshmen and their families.

Welcome to Yale, where for the ninth time in 35 years, campus life also includes picket lines.

This strike is the second since Yale and locals 34 and 35 began bargaining nearly 18 months ago. Unlike the five-day walkout in March, this strike has no end date, and union leaders have told workers to prepare for being out of work indefinitely.

It is hard for the students, but much harder for the workers. And we are skeptical that it will pay off for those making the biggest sacrifices. For many workers, going on strike means forgoing income, besides $150 a week picket pay — a particularly difficult move during weeks when Yale employees may have to buy clothes and supplies for their children returning to school.

As with any strike, it is impossible to know whether the hardship of striking now will pay off with improved wages and benefits when contracts are finally signed. But given the actions of union leaders for the year and a half since bargaining began, we find it difficult to believe this strike will be worth the sacrifices.

For the majority of negotiations, union leaders have not made earnest attempts to reach a settlement. Instead, they have focused more on publicly decrying Yale positions and spreading skewed information about the bargaining process. Negotiations began with a now-laughable attempt to mend the bitter relations between Yale and the unions, with President Levin announcing he would offer generous contracts and union leaders saying they would move past old grievances.

Whatever workers and union leaders envisioned, the contracts Yale offered in June did not match many union members’ expectations of what a “generous” offer would include. Despite increases in raise offers, the University should still increase its pension offers to compensate for years of low pensions. And union leaders, who decided to strike three months ago — effectively placing strike plans over progress at the bargaining table — have continued to focus on public efforts to undermine the University instead of earnest bargaining that might lead to a resolution.

Besides strategic choices, union leaders seem unlikely to achieve major contract gains given the lack of progress so far. In part, the unions are facing bad timing — in the year and a half it has taken to bargain, the economy has soured, leading to many layoffs in the area and city and state unions being asked for givebacks. That does not mean Yale workers do not deserve more, but it does mean union leaders should not ignore the context.

Bargaining will resume today with the presence of New Haven Mayor John DeStefano Jr., who brokered the last contract between the two sides in his office seven years ago. Perhaps DeStefano can make headway where negotiators have failed thus far. But given the behavior of union leaders for the last 18 months, we fear the strikes that have sullied this year’s welcome will mean little more than inconveniences for students and unfulfilling sacrifices for the workers who make them.