Does life satisfaction change by region over time? Use the lifesat_childmort data from Example 2.15 to explore this question.

Data from Example 2.15

The World Happiness Report [Helliwell et al., 2019] collects data from the Gallup World Poll global survey that measures life satisfaction using a “Cantril Ladder” question: think of a ladder with the best possible life being a 10 and the worst possible life being a 0.