“Percentage of marriages that end in divorce” is an underspecified concept. There is only “percentage of marriages that end in divorce after n years”.
According to this NYT article, it is incredibly common to report (new divorces / new marriages) as the “% of marriages ending in divorce” – and this is misleading because it makes a decline in marriages look like an increase in the probability of divorce. The very large figures, like 50% or above, seem to be indeed reporting this figure.
You could adjust for changing demographics of course, but one would think that introduces some uncertainty into the measurement.
I phrased my comment clumsily as a reason to link to something that would clarify the underspecified comment of a “divorce rate”. It seems like 40% is a realistic figure for some countries after you do demographic adjustment, but, insofar as a higher figure is reported, it is because of a misunderstanding.
I will think of a way to clarify this claim, or delete it entirely.
Fair enough. I have removed that part of the post.