LAUSR

Abstract SAFE (Sustainability Assessment by Fuzzy Evaluation) is updated with data starting at 1990 and reaching 2016. Older versions of the model have been refined to remove outdated indicators and incorporate new ones. Also new modules were added to expose various dynamic features of sustainability worldwide. In all 69 time series of basic indicators are used to generate various intermediate sustainability indices and finally an overall index for 164 countries which are ranked accordingly. Data are manipulated statistically to introduce memory, then normalized in [0, 1], and finally passed through a sequential fuzzy reasoning system to obtain the SAFE sustainability index. A sensitivity analysis reveals those indicators with the highest potential of improving sustainability. Most countries have made a modest progress towards sustainability over 1990–2016. Interestingly, North America shows a small decline. Another counterintuitive result is the relatively low ranking of advanced countries such as South Korea, a fact explained satisfactorily by the model. Finally, there is a high correlation of the SAFE index and per capita income which implies that sustainability is predicated on a reasonably high economic level.