This tutorial is part of the guide for the Montreal Policy Simulator.

Case Study of a Permit System

This tutorial examines a permitting system where demand from one substance moves into the other. This may help explore how multiple substances may interact with each other in the market.
Contents

Motivation

In the previous tutorial, we both introduced our simulation to multiple substances and to policies which can manipulate across two substances. However, that prior policy didn't directly model how demand might be changing in the market. For example, a permitting system could cause pressure where some consumers of a refrigerant will move to an alternative when permits become scarce. In this tutorial, we will tell our simulation about how we expect demand may shift from one substance to another.

Adding Permits

We will express our permitting intervention as a policy which limits use of a substance to a target. Go ahead and create a new "com permit" policy with the following properties for HFC-134a set through the limit tab:

This will model a permitting system requiring an annual reduction of 2% followed by 5% for HFC-134a. Note that we won't yet introduce the idea of demand shifting so please leave "displacing" as nothing. See the gif below for a video demonstration of how to do this step.

Animated GIF of adding the new policy

New Simulation

Let's quickly take a look at what this policy looks like. Go ahead and make a new simulation which shows the impact of this permitting system on its own. You may also add this to the combined policy scenario. See the gif below for a video demonstration of how to do this step.

Animated GIF of updating the simulations

Adding Displacement

Right now, the permitting doesn't yet exhibit that pressure which causes an alternative like R-600a to go up. We can change this by modifying the policy to say that we "displace" into R-600a. After adding this into the permits policy, go ahead and take a look again at the simulations to see how the two substances are interacting with each other. See the gif below for a video demonstration of how to do this step.

Animated GIF of adding displacement

Conclusion

In this tutorial, we explored adding a policy into our simulations which specifically considers how demand in one substance may impact another. In the next tutorial, we take a look at the editor tab.