Earlier this year, a wave of high-profile strikes ushered unions back into the national spotlight. But as the United States’ so-called “hot labor summer” gives way to an equally enthusiastic fall, we must contend with the reality that while union activity is higher than it’s been in years, union density remains dismally low. The share of employees who belong to unions has been falling for decades and reached an all-time low of 10.1 percent in 2022. The share in the private sector was even lower