What does the following mean: "supply has positive elasticity”? What confuses me in particular is that I always thought of the concept of ‘elasticity’ with respect to something. That is, supply of x can be elastic with respect to y.
Am I missing something?
Price elasticity of supply is: $\frac{dQ_s}{dp}\frac{p}{Q_s}$. Because supply slopes upward $\frac{dQ_s}{dp}&gt;0$. $Q_s$ and $p$ are also positive so    $\frac{dQ_s}{dp}\frac{p}{Q_s}&gt;0$.