Based on a Bureau of Labor Statistics report showing that the number of striking workers is the highest since 1986, many have celebrated the return of the strike. With the wave of teachers’ strikes over the past year, the successful string of hotel worker strikes by Unite Here, and most recently the Shop & Stop grocery workers’ strike in New England, there are certainly many reasons to be hopeful.

Labor activists are by nature optimists. We must be — otherwise, how do you inspire workers to take action and move forward? Struggle feeds upon struggle, and the notion that striking is a good thing helps spur others to action, as it did in Arizona and Oklahoma after the West Virginia teachers’ strike. So, talking about and promoting strikes is a good thing.

But optimism can’t be a substitute for sober analysis. Truly reviving the strike is going to take some radical changes to labor strategy, given the depth of labor’s crisis. It’s important to take a close look at the numbers. And the numbers show that there was a substantial teacher strike wave accompanied by a modest strike activity in the private sector.