Graphical representation of the consumption function, where a is autonomous consumption (affected by interest rates, consumer expectations, etc.), b is the marginal propensity to consume and Yd is disposable income.
<a href="//commons.wikimedia.org/wiki/User:Blackngold29" title="User:Blackngold29">Blackngold29</a>
<span class="int-own-work" lang="en">Own work</span>