Some studies are content with establishing simple correlations, while others involve sophisticated econometric analysis, attempting to ascertain the existence and direction of causality. Yet other studies involve complex systems with feedback loops or large simulation models with scenario analysis. Inevitably, they reach different conclusions even when they analyze the same body of data because of differences in perspectives, levels of aggregation and methods of analysis. Another critical difference is the degree to which the studies take into account the relevant context and which intervening, mediating or interacting variables have been included in the analysis. .
