Here is a very good Amanda Ripley NYT piece, more than just the usual. Here is just one of numerous interesting bits:
In 2006, socioeconomic status had explained 17 percent of the variance in Americans’ science scores; in 2015, it explained only 11 percent, which is slightly better than average for the developed world. No other country showed as much progress on this metric. (By contrast, socioeconomic background explained 20 percent of score differences in France — and only 8 percent in Estonia.)
Generally speaking, the smartest countries tend to be those that have acted to make teaching more prestigious and selective; directed more resources to their neediest children; enrolled most children in high-quality preschools; helped schools establish cultures of constant improvement; and applied rigorous, consistent standards across all classrooms.
For the United States, math is still clearly the weakest subject, in fact at all income levels.