Doesn’t everyone have an opinionated relative who says he’ll never retire because he had a friend who retired and then died the next week (month, whatever)? As much as I look forward to retirement, I sometimes wonder if those who think it isn’t such a good idea might be right. What will I do with my time? Perhaps I won’t feel productive. My brain will turn to mush. Well thank goodness, someone has done a study to look at just this issue. Here’s a NY Times article about a study purporting to show that early retirement reduces your memory.
My first response was, “Wow, someone really designed a study that shows a relationship between working and mental ability!” But the more I looked at the data in the graph, the more I doubted that this study could say anything. Admittedly, I’m basing these comments on the graph provided with the New York Times article. If you are interested in the full study, it is available for free at the Journal of Economic Perspecives’ web site.
My first concern is that it is a correlation study. Anyone who has taken statistics has heard a professor beat into them, “Correlation doesn’t prove cause and effect.” Just because two things seem to be related doesn’t mean that one causes the other. The sun comes up about a half hour after I get out of bed every morning, but my getting out of bed does not cause the sun to come up. The sun coming up doesn’t cause me to get up either, though the fact that the day is beginning is related to the fact that I need to get up and head to work.
In this case the researchers looked at aggregates of two numbers for different countries, how well 60 to 64 year olds did on a simple memory test and what percentage of 60 to 64 year olds were retired in that country. On average people in countries that had more people still working did better on the memory test. But if you look closer you will see that this is far from conclusive.
There are only 13 countries in the analysis and they are scattered all over the plot. For instance, the Netherlands and Spain had about the same early retirement rate but their scores on the memory test were nearly 30% apart. Austria and Switzerland had similar scores on the memory test but their early retirement rates are nearly as far apart as any two countries in the study. You can look at the same plot and say that people in countries further from the equator did better than those in countries nearer to the equator. Since the study is comparing countries, could there be other factors that might cause this sometimes tenuous relationship? Perhaps education level, diet, income… Could you make a similar graph using these other factors?
What do you think? Is this study intriguing? Does work improve your memory? Or do you think you’d be more intellectually stimulated in other activities?