PS Falling Asleep or Drifting Off ?
I cannot resist adding a postscript to last week’s Newsletter #240 on sleep.sleep . I had no sooner published it than I was advised about a new study. We have different ways of describing how we move from awake to sleep. Researchers at the UK Dementia Research Institute looked precisely at this issue. They used a sophisticated algorithm to analyse ECG charts from people as they made the transition to sleep.
It seems that we “fall” asleep. There is a single tipping point. It is not a gradual transition at all. They tracked the same people over many nights. They were able to predict with 97% accuracy when the tipping point happens. The researchers hope to use the results to help people who cannot get to sleep. There is hope for the older sleepers disturbed nights. They can also use the transition to track changes in the brain.
The Value of a Statistical Life
Governments need to make policy decisions. To compare options, they need to make sophisticated cost/benefit trade-offs. Comparisons across alternatives need a common metric for value. In most cases this must be monetary value. Many parts of these analyses are already expressed in monetary terms. The cost of the construction of a new bye-pass around a busy town. This would improve traffic flows and potentially reduce accidents. However, it might increase pollution in the local area and increase mortality. Governments need some metric they can attach to the value of a life.
They use the “value of a statistical life” (VSL). This is the value of a small mortality risk reduction that would prevent one statistical death. It is not the same as saving an “identified life”. We have all been touched by a crowd sourcing campaign for a sick child in need of a last chance treatment. We can value that life much more highly than the improvement in a statistical risk of dying.
How Do They Calculate the Value of a Statistical life.
There are two main ways. The first is to ask people what they might pay. For our example, let’s use our car safety exercise. We are told that on average 5 people out of every 100,000 are likely to die because of a car accident. We are asked how much we would be prepared to pay to reduce that from five to three. Suppose we say £150. The Value of a statistical life is £150 x 100,000/3 or £5m per statistical life.
Alternative approaches look at the labour market. The compare comparable jobs but with different risks of dying. They look at the premium paid for the risk and use that to compute the VSL.
The VSLs around the World are Increasing
We would expect higher VSLs in more affluent countries. However, if we standardize for income or GDP the curve still goes up. It seems that Societies are valuing life more highly. Lots of people have tried to explain this. It appears that we are changing our attitude towards death. We are becoming increasingly averse to it. Perhaps it is because we know less and less about it. Because we see death less and less often. One hundred years ago child mortality and maternal death during childbirth was much higher. Then we might have experienced the death of a sibling.We might have lost a mother.
A Two Part Story
I will continue this discussion next week. In the meantime, you have some “homework” in preparation. The figure shows a different way of looking at life. It looks at death. There were 2,854,838 Americans who died in2019. There were more people over 100 (30,731) than children that died at birth. The most likely age, known as the mode, was 87 years old. Just under 77,000 people died at that age. Life Expectancy, as defined by the Government statisticians, was 78.8 years. Half the deaths occurred before the age of 77 and half after the age of 77 (the median). If we take an average across all ages it is 73 years.