iii) future variations in safety valued on the basis of the future VOSL, [m.
0], so that it would be equally legitimate to deal with future safety effects by valuing these on the basis of the same VOSL as current safety effects and subjecting the resultant benefit measure to no discounting.
Now consider the product of the discount factor, [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] and the future VOSL, [m.
The result given in (11) indicates that, as an alternative to valuing future safety in terms of the future VOSL, mt, and then subjecting the resultant benefit measure to the same discount factor as is applicable to future variations in income, one could equivalently value future safety effects in terms of the current VOSL, [m.
It therefore transpires that for those cases of the social welfare function specified in (6) that are bracketed by the utilitarian and log-linear forms, impartiality entails that future safety effects valued in terms of the current VOSL, [m.
Recent published estimates for the VOSL have been considerably higher than the central value used here; this has been historically the case for estimates derived in U.
Because individuals with pre-existing disease are more susceptible to adverse effects from air pollution, and deaths are not solely additional but consist of deaths brought forward and additional deaths, valuing years of life lost would be preferable to estimating the VOSL per se.
This value is not, however, a true VOSL value but rather an adjusted estimate of VOSL allowing for an estimated minimum reduction in life expectancy (based on current value judgments) and possible maximum reduction in the quality of life because of the health effects of air pollutants.