Equilibrium functions for the two types of model.

<p>Shown are : MacDonald <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115875#pone.0115875.e210" target="_blank">equation (19</a>) (gray), and SWB <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115875#pone.0115875.e335" target="_blank">equation (21</a>) (black), for calibrated model parameters of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0115875#pone-0115875-t004" target="_blank">Table 4</a>