Saturday, November 17, 2012

Why hasn't more use been made of ACSA for measurement of progress?

What is ACSA? It seems to be an acronym for a lot of different things, but the particular ACSA I am referring to is Anamnestic Comparative Self-Assessment. This is an approach to measuring progress which was first suggested by Jan Bernheim about 30 years ago.

The distinctive feature of ACSA is that it asks survey respondents to rate their current wellbeing by comparison with their memory of the best and worst periods of their own lives (with the best period being given a rating of +5 and the worst period being given a rating of -5).

ACSA is an alternative to the conventional question which asks people to rate their current lives using abstract universal anchors. For example, the Cantril scale gives ‘the best possible life’ a rating of 10 and ‘the worst possible life’ a rating of zero.

In terms of measuring progress, ACSA has the merit of using anchors that could reasonably be expected to more stable over time than perceptions of the best possible life. As explained in recent posts (here and here), when people are asked to rate their own lives relative to the best possible life, they are likely to be making that assessment relative to a moving target. If they see their own lives improving in line with their perceptions of the best possible life, they can be expected to give similar ratings to their lives in successive surveys. It should be obvious to everyone that it is a mistake under those circumstances to interpret stable ratings as implying an absence of progress.

A major study comparing results obtained using ACSA and a conventional measure of life satisfaction for a large number of adult hospital patients suggests that ACSA is indeed less subject to biases of various kinds. For example, the results obtained using ACSA were more responsive to a major objective change in the prospects of end-stage liver disease patients following liver transplantation. The conventional measure of life satisfaction did not capture adequately the impact on wellbeing of the life-threatened situation of these patients prior to transplantation, or the fact that transplantation restored them to an almost normal life. The study is reported in Jan Bernheim et al, ‘The potential of anamnestic comparative self-assessment (‘ACSA) to reduce bias in the measurement of subjective well-being’, Journal of Happiness Studies (2006). An ungated article providing a brief discussion of ACSA is available here.

The potential strengths of ACSA relative to conventional measures of life satisfaction are most obvious where the focus of research is on changes in the wellbeing of individuals over time. A potential weakness of ACSA arises in comparing ratings of different individuals, even though research findings suggest that there are common elements in memories of different people concerning the best and worst periods of their lives (the best periods often involve such things as birth of a child and the worst periods such things as unemployment). It seems likely that many people in high-income countries would perceive that the worst periods in their lives were not as bad as those experienced by vast numbers other people in the world. They might also perceive that the best periods of their lives were better than those of people with fewer opportunities.

One possible way to combine the ACSA ratings of different people would be to place them on the same scale as conventional ratings using the Cantril scale.  When I did that for myself, I gave a rating of 8.5 to my current life, a rating of 9.5 to the best period of my life and a rating of 6.0 to the worst period of my life. That implies an ACSA rating of about 2 [10*(8.5-6.0)/(9.5-6.0) – 5]. That is also the ACSA rating I gave to my current life when I asked myself the ACSA question directly. Such introspective exercises don’t necessarily mean much, but this one suggests to me that the underlying concepts used in ACSA are compatible with the Cantril scale. I urge other people to do the exercise to see if they also get sensible ACSA estimates. 

As far as I can see there is no reason why surveys could not ask people to give a rating to the best and worse periods of their own lives on the Cantril scale, immediately after asking them to rate their current lives on that scale. The Cantril scale is far from perfect as a methodology for making interpersonal comparisons of well-being, but the results it provides in that context seem to make more sense than in making comparisons over time. The calculation of ACSA scores in conjunction in longitudinal surveys using the Cantril question provides potential for development of meaningful measures of perceptions of progress.

I don’t know the answer to the question I asked at the beginning of this post. More use should be made of ACSA. It seems to me that including ACSA type questions in longitudinal studies, such as HILDA, has potential to provide useful information.

No comments: