Professor Froomkin’s comment about morbidity rates reminds me that I promised to explain why on earth I was looking into the statistics on life expectancy. The reason is the bearing of those statistics on the debate over immigration. One of the most important statistics concerning a country’s economy is the proportion of the population that is economically productive. In the standard life cycle model, the population is divided into those too young to enter the labor force, those who are retired from the labor force, and those who actually produce the goods and provide the services that we all need to survive. When Social Security was instituted, only a small fraction of the adult population could be expected to live more than a few years beyond a retirement age of 65. With the improvements in child mortality and early adult health, even the increasing numbers of retirees could be supported adequately by the labor of those in the productive years intermediate between childhood and old age. [I am simplifying all of this to keep down the length of this post.] But as those who make it out of childhood live longer and longer, the balance shifts.
Look at it this way. If you are in your thirties or early forties, then most of the men and women who will, when you are seventy, grow your food, truck it to your local supermarket, care for you when you are sick, and amuse you when you are not have not yet been born. If there are too many oldsters like you, say in 2055, and too few young ‘uns, then regardless of how much you put into your 401k, you are going to be in trouble.
What is the most natural solution? Let in a whole bunch of immigrants who are either children or else of childbearing age, and make sure they get enough to eat, good health care, and good educations. That way, when you are a senior citizen like me, you won’t starve to death or die for lack of a doctor to look after you.
In short, a steady flow of immigrants is in the rational self-interest of those already here. Without immigration, the situation is only going to get worse, as it has for example in Japan.