Improving Sustainability Indices through Judicious Inclusion of Indicators

Human societies are intimately connected to their supporting environments, thus suggesting that societies should be referred to as socioecological systems. To be ?sustainable?, the conditions of socioecological systems must meet two criteria. First, the conditions must be those that can persist for the long term, given the physical constraints of the planet and other limitations. Second, the conditions must be desirable (there are undesirable system conditions that can persist indefinitely, such as violent conditions in collapsed nation-states). Desirable conditions are often described as sustainability targets or goals, and for many of these goals, one or a set of indicators are chosen to track the progress of the system towards the goals. However, the relevance of these indicators to sustainability goals, and their independence from each other, is not well-known. Often, the choice of indicators is driven solely by data availability. Some indicators, such as rates of infant mortality, have a linear relationship with sustainability; the higher the rate, the lower the sustainability of the socioecological system. Others, such as per capita GDP, have a more complicated relationship with sustainability; countries with the highest per capita GDP are not necessarily the most sustainable ecologically, socially, or even economically. Additionally, indicators often represent conditions in socioecological systems that are closely linked. These interactions may result in a situation where policies meant to improve one indicator causing a decline in another, resulting in no net increase in sustainability conditions. For example, to decrease the number of cases of illnesses caused by poor sanitary conditions, one policy may support the installation of traditional sanitation technology, which uses water to dilute and transport waste. This technology may then increase the number of people experiencing water stress by increasing water competition during drought conditions. Sustainability indices are increasingly used as a way to aggregate many environmental, social, and economic indicators into one easily-understandable value that can be tracked over time, to measure progress towards goals. If interactions among indicators are not known or accounted for, sets of correlated indicators could receive a higher weighting and therefore bias those sustainability indices that use aggregation methods such as summation. If indicators, and the aggregation of these indicators into indices, are to be useful, there must be a more thorough accounting for the ways in which they relate to sustainability goals.