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WELLBY: an overall measure of wellbeing effects

One of the major challenges when we want to include wellbeing in our societal decisions is that we don't have a consistent measure of the parameters that affect our wellbeing. For wellbeing to be included in decision-making on an equal footing with other areas, we need a language for how much wellbeing a social change creates. Like the UK Treasury, we use the WELLBY (wellbeing-adjusted life year) unit. The UK Green book[1] describes a WELLBY as a change in life satisfaction of one point on a scale of 0-10 for one person for one year. 

WELLBY - with and without monetization

With the WELLBY device, we can compare social change of different kinds. Below is an example of two interventions: one has reduced loneliness in senior adults, while the other has reduced homelessness. Although we measure the change the interventions create, it's difficult to compare them - which is more valuable, reducing loneliness or alleviating homelessness? By translating the changes to WELLBY, we can see which intervention creates the most wellbeing. By comparing the cost of the interventions to the number of WELLBYs they create, we can analyze how effective they are in increasing overall wellbeing. 

In many contexts, cost-effective analysis (CEA) is enough when we need to make informed decisions. In other contexts, we need cost-benefit analysis (CBA) for changes to be included in economic assessments. By putting a monetary value on a WELLBY, we can translate changes in wellbeing into the common language of money, making it possible to incorporate wellbeing changes directly into existing economic calculations. 

Figure 5: Example of comparison of 2 initiatives with and without WELLBYs and social value


[1] H. Treasury, Wellbeing Guidance for Appraisal: Supplementary Green Book Guidance. 2021 [Online].