Jon Peltier took a look at yesterday’s popular Health Care graph from National Geographic, and saw a few problems. From bad axes to choosing two variables with no correlation, he thought he could do better and constructed the bubble XY plot shown.
The US is an obvious far outlier. You can imagine an upward slope in the green markers, perhaps steeper than 45° in this plot. The correlation is not really strong, nor is it negligible. Excluding the US, the R² value is 0.52 including Mexico and 0.48 excluding Mexico.
But he didn’t stop there. An R² of 0.52 isn’t very good, so he added some missing countries to see if it would improve.
Inclusion of these countries increases R² to 0.56, probably since most of them fall within the dens upper range of the previously included countries, and one point, Turkey, falls below and left of the rest. In all of the regressions, the slope of the line is 1.9 years per $1000 of spending, and the Y-intercept implies that we’d live to 73.5 without spending a dime. At the level of spending of the US, the relationships predict a life expectancy of 87.5 years.
Again, still not much of a correlation between spending and life expectancy. Not terribly surprising, since you can spend as much money as you want on medicine but you’re probably still not going to solve poor living conditions or poverty.
