Try downloading the Unit 2.1 study guide. There are loads of supply and demand diagrams in there! To make it for kidneys, simply put the words “kidney market” at the top of the graph! Wualla!

In fact, Environmental Economics is covered in our course… if only on the surface. You should download the study guide for Unit 2.4 – Market Failure. This unit discusses pollution, global warming, environmental protection, although in the context of negative externalities.

You may also explore the “Environment” category on this blog, I have written several posts over the years relating to the environment. http://welkerswikinomics.com/blog/category/environment/

Enjoy! – Jason

Loving the blog. You make economics so much more interesting with real life examples.

Anyway, I’m still a little confused with why price elasticity of demand varies at every level in a straight line demand curve. “It is wrong to say that price elasticity is constant”. BUT WHY? Mathematically, PED is %change in q/ % change in P, which means it is replica of dy/dx, which calculates the gradient. But the gradient does not change when it is in a straight line.

I just find it a little weird.

Good question. It depends on how your teacher taught you to draw the lines. I teach my students that SRAS is curved, relatively flat below full employment and relatively steep beyond full employment. I also teach them to draw a vertical long-run AS curve at the full-employment level of output. This represents where the nation would produce if all resources were fully employed (corresponds with the nation’s PPC). AD I simply draw as a straight downward sloping line, no curve to it.

Hope that helps!

Jason