Path diagram of structural equation models for state characteristics and outcomes.

<p>Each variable is normalized between 0 and 1 by dividing all values by its largest value in the thirty year time span. SEM diagrams are shown for the models in a) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123339#pone.0123339.e001" target="_blank">Eq (1)</a>, b) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123339#pone.0123339.e002" target="_blank">Eq (2)</a>, and c) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123339#pone.0123339.e003" target="_blank">Eq (3)</a>. All relationships, shown as arrows, denote free parameters identified by the model and given in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0123339#pone.0123339.t001" target="_blank">Table 1</a> with their statistical significances.