#2080: Cohort and Age Effects explain

[Cueball as a news anchor is sitting at a desk with hands folded in front of him on the table.]

Cueball: Tonight: Are Millennials killing the joint replacement industry?

[To the left of Cueball is a presentation which includes a two by two table with a header above the table. Each of the two rows and columns are labeled, with rows entitled ‘Baby Boomers’ and ‘Millennials’, and columns entitled ‘Knee’ and ‘Hip’]

;Operation rate per 100,000

;Baby Boomers:

Knee: 720

Hip: 390

;Millennials:

Knee: 1

Hip: 3

[Caption below the panel:]

Stats Pet Peeve: People mixing up cohort effects and age effects.