This smells like a composition effect. Have you checked that this is not just due to e.g. aging of the population; or driven by the rise in immigration?
On the aging thing I’ve just done a rough estimate. The median age increased about 3 years between 1999 and 2019, and as it’s around 40 which is before the mid-life crisis (life satisfaction being U-shaped as you age, the lowpoint around 50), an age increase of 3 years would if anything lower happiness. (Of course it would be a mix of some going down and others up depending on their ages, but the overall effect would presumably be down. Incidentally the bottom of the U-shape hasn’t noticeably got older as the population aged over this period.)
But the effect is small anyway—the median, getting 3 years older, would lose about 0.07/10 points life satisfaction (when expressed as a score out of 10), which is only about 10% of the 1999-2019 change, as well as in the wrong direction.
The aging did occur to me, but without doing the numbers I doubt it would have an effect that fast on happiness, and certainly not that fast on misery.
Re immigration, research shows immigrants mostly take on the happiness of the country they move to, partly retaining their previous happiness. And as most recent immigration has been from less happy countries (eg Eastern Europe), I’d expect the effect to be a small fall in happiness not a rise. Though again without doing the figures I doubt it would be big enough to affect the general shape of the graphs.
This smells like a composition effect. Have you checked that this is not just due to e.g. aging of the population; or driven by the rise in immigration?
On the aging thing I’ve just done a rough estimate. The median age increased about 3 years between 1999 and 2019, and as it’s around 40 which is before the mid-life crisis (life satisfaction being U-shaped as you age, the lowpoint around 50), an age increase of 3 years would if anything lower happiness. (Of course it would be a mix of some going down and others up depending on their ages, but the overall effect would presumably be down. Incidentally the bottom of the U-shape hasn’t noticeably got older as the population aged over this period.)
But the effect is small anyway—the median, getting 3 years older, would lose about 0.07/10 points life satisfaction (when expressed as a score out of 10), which is only about 10% of the 1999-2019 change, as well as in the wrong direction.
The aging did occur to me, but without doing the numbers I doubt it would have an effect that fast on happiness, and certainly not that fast on misery.
Re immigration, research shows immigrants mostly take on the happiness of the country they move to, partly retaining their previous happiness. And as most recent immigration has been from less happy countries (eg Eastern Europe), I’d expect the effect to be a small fall in happiness not a rise. Though again without doing the figures I doubt it would be big enough to affect the general shape of the graphs.