Joseph Sternberg is absolutely right about the adverse effect of Elizabeth Warren’s proposal to tax baby boomers (“How Do You Tax A Baby Boomer?,” Political Economics, Sept. 13). Yet it surprises me how stuck in a 20th-century work-retirement model even the usually perceptive and insightful Mr. Sternberg seems to be.

For a nation that worships youth, America spends a lot of time obsessing about retirement. A cottage industry of financial journalists and bloggers regularly bombards us with advice: when to draw Social Security, where to live, how to invest our savings.

Mr. Henderson notes Paul M. Romer’s ideas relating the structure of incentives to innovation using the profoundly crucial role patent policy has played in pharmaceutical innovation. But in the 21st century governments have countered the otherwise positive impact of patents with all manner of pharmaceutical price controls.

If we view the lives of Western women through the lens of 21st-century age demography, the limitations of the lifestyles Ms. Komisar describes become even more apparent.