The positive developments include falling crime rates, fewer abortions and a remarkable decline in teenage pregnancies. Less encouraging are the increasing number of single-parent families and the huge prison population. On health matters, cigarette-smoking continues to drop, but drug use doesn’t.

Crime has been declining steadily, with rare exceptions, for the past couple of decades. Since 1995, the murder rate has been reduced almost by half, and violent crime is down by more than 43 percent.

Although compared with almost any other country, the U.S. is plagued by an epidemic of gun violence, firearms-related homicides — in keeping with other crime data — have declined sharply since the 1990s.

Bennett and other social observers have analyzed many indicators, including educational and economic data. The state of the family is always central. Americans marry and divorce more than the citizens of any other industrialized nation.