About the first question, my own recent research on apparel and rental housing indicates a substantial downward bias in the CPI over much of the twentieth century, diminishing in size after 1985. Incorporating these findings into the Boskin matrix would reduce its 0.6 percent annual upward bias...

Backcasting upward bias in price index over long periods of time yields levels of real consumption two or four centuries ago that are implausibly low, raising the possibility that price index bias for important products may have been zero or even negative at some point in the past. This paper...