This paper presents a general impact assessment relationship, intended to contribute to the development of social life cycle analysis. This relationship and the conditions of its use are called the "Wilkinson pathway". When used for comparisons, the pathway assesses the anticipated change in the infant mortality rate caused by a change in income distribution in the population of a country, itself generated by an important change in a life cycle. Since the 1980s, numerous authors have examined the relationship between income inequality and human health. Without formally proving so, these studies suggest that increases in inequality have negative consequences for health. First, this effect is re-examined using the most up-to-date time series data. Econometric modelling allowed calculating the coefficients of variation of infant mortality in relation to variations in income inequality for member and non-member Organisation for Economic Cooperation and Development (OECD) countries, taking into account the lag time. Then, a method to translate the effect of an important economic change in a life cycle on income distribution is proposed. The econometric estimations show that a 1 % variation in income inequality leads to an approximately equivalent variation, with a lag time of about 15 years, in infant mortality in OECD member countries. The effect is two times larger than in non-OECD member countries. Together with input-output data, labour productivity and average wages in different economic sectors, this information makes it possible to quantify the probable effects of an important change in the life cycle production stage on income inequality and then infant mortality. Due to data constraints and the many assumptions made, the tools and results presented here should be used and interpreted cautiously. Above all, what is involved is a comparative method. An isolated result must not be interpreted in absolute terms. This work is in line with efforts to formalize general pathways allowing a comparison of socioeconomic impacts linked to various important changes in the production stage of life cycles. There are diverse prospects for improvement. A challenge for further research will be to propose methods enabling assessments of the socioeconomic impacts generated in life cycle stages other than production.