The tight labor market in the U.S. is leading to a shift in the balance of power between labor and capital, giving more leverage to workers. This manifests itself in a variety of ways.
For instance, workers are less reluctant to leave their jobs in search of better pay or working conditions. This is showing up in the rate of workers quitting their jobs at the highest level since 2001. It also gives unions the confidence to go on strike in hopes of getting a better deal, as we've seen with the United Auto Workers in its negotiations with General Motors Co.
In this environment, the rationale for joining a union hasn't looked this good in a very long time.
Unionized workers tend to receive higher wages and greater benefits than their non-unionized peers. Who wouldn't want that? There are, of course tradeoffs with being in a union: loss of flexibility, membership dues, contract negotiations with employers that can come up empty, and periods without work in fallow economic times or during strikes. But all else being equal, a good union job that lowers the risk of unemployment would be the best of both worlds for many workers.