Box 1. Estimating the VSL for Morocco

Several studies have estimated the VSL in many countries on each continent, and these results were later used in meta-analyses [25] [27] [28] [29] . The average VSL for nine high-income OECD countries has been estimated to range from US$4.4 million to US$4.8 million (2011 prices, at market rates) [8] [30] . These numbers reflect the median and the mean VSL estimates from a database of quality-screened willingness-to-pay studies conducted in high-income OECD countries.

To derive the VSL for Morocco, we use the benefits transfer method, accounting for differences in socio-economic parameters between the two sites. The transfer is conducted based on the formula:

V S L M o r o c c o = V S L O C D E * [ ( GDP / capita ) M o r o c c o / ( GDP / capita ) O E C D ] e


VSLMorocco = VSL for Morocco

VSLOECD = VSL for OECD countries (average)

(GDP/capita)Morocco = GDP per capita in Morocco

(GDP/capita)OECD = GDP per capita in OECD (average)

e = income elasticity to the VSL (varying from 1 to 1.4, with a central estimate of 1.2)

Accordingly, the VSL for Morocco is estimated between US$183,000 and US$200,000, with an average of US$191,500. We use this figure to value the economic cost related to premature deaths due to air pollution.

Source: based on [31] .