Why has the employment rate fallen so far in the United States relative to the euro zone?

It is widely claimed that the US labour market works better than its counterpart in the euro zone. Yet over the past 20 years, the employment rate has declined considerably in the United States relative to the euro zone. Why? This is not linked to an excessively high level of labour costs in the United States, since income distribution is skewed against wage earners in the United States and not in the euro zone; It is not due either to the low level of wages at the bottom in the United States - which could discourage low-skilled people from looking for a job - since it is the employment rate of skilled people that has fallen; The employment rate of over-60s has risen sharply in the euro zone, which explains some of the broader trend; Surveys seem to show similar levels of labour force skills in the United States and the euro zone as a whole. However, the trend in hiring difficulties reported by companies shows a growing skills mismatch problem in the United States; The deteriorating health of Americans is often cited as one of the causes of the decline in the employment rate in the United States ; The decline in geographic mobility appears to be one of the causes of the decline in the US employment rate.