How to make summer learning count, U.S. deterrence in the ‘gray zone,’ why so many Americans are stuck outside the middle class, and more.

Tips from RAND research for effective summer learning programs; America’s competitors in the “gray zone” short of war; why it’s so hard to get into the middle class; China-Iran cooperation; and a post-pandemic wake-up call. For more information on this week’s episode, visit rand.org/podcast.