Surveys undertaken by the Pew Research Centre enable comparisons to be made between ratings of quality of life at the present time and ratings of quality of life five years ago. The results for the U.S. (here) indicate that while respondent’s average ratings of current quality of life had moved up and down by small amounts when asked at various times over the last 40 years, they consistently reported that their quality of life was substantially worse five years ago - indicating that they perceived that they had experienced ongoing improvements in the quality of their lives.
These results suggest that people can perceive that the quality of their lives is improving even though their reports of quality of life at different points of time indicate that there has been no increase. Some people might suggest that this means that people have faulty memories of the quality of life they enjoyed in the past. I acknowledge that memories can be faulty, but I see no reason why people should systematically view the past as having been worse than the present. On the other hand, I can think of a good reason why current reports of quality of life may not show much change over time in the face of objective evidence of improvements in standard of living.
The use of survey information to measure the current quality of life involves the implicit assumption that when people rate their quality of life they do so relative to absolute standards. Respondents in the Pew survey are prompted to think in terms of a ladder of life in which the top step represents the best possible life and the bottom step represents the worst possible life. The use of successive surveys to measure change in the quality of life entails the assumption that perceptions about what constitutes the best possible life and the worst possible life remain fixed over time.
When you think about this, however, how can it be possible for anyone in a relatively high-income country to know what the best possible life, or the worst possible life, might be like throughout their own life-time? If you asked someone to rate how satisfied they were with life in the 1940s they would not have had much idea of the kind of life they might be able to live in 60 years time. They would not have known that many of the household appliances and communications devices that we now have would be within reach within their own life-time. They might have wished that such things could be invented and made affordable – just as I wished as a child in the 1950s that I could have a 2 way wrist radio like the one Dick Tracey had – but I don’t think such things would have been contemplated as actually attainable.
It is widely accepted among happiness researchers that in high income countries increases in standards of living may not translate to increases in happiness because aspirations tend to rise as incomes rise. I am not sure that many have realized, however, that if this process involves a change in perceptions about the best possible life it is changing the scale against which people are assessing their quality of life. Thus a person who felt that her quality of life had improved over time might report ratings of her quality of life at different points in time which indicated that she had stayed on the same rung of the ladder. The apparent conflict of perceptions has occurred because the ladder has shifted upwards.
If our aim is to use surveys to measure of happiness, as an emotion, it may be appropriate for the ladder (measurement scale) to move upward as perceptions change about the best possible life. If we are attempting to measure quality of life, however, we should recognise that an upward movement of the ladder - which occurs because of a change in perceptions of the best possible life - is itself evidence of improvement in the quality of life. In my view we should accept what people say when they report ongoing improvements in the quality of their lives and also to accept that this will not necessarily make them feel any happier than in the past.
In my next post I explore the possibility of using perceptions about changes in quality of life to construct a chain index showing how the perceived quality of life has changed over time.