Quick Scenario Analysis with Tree

The Quick Scenario Analysis with Tree page can be accessed from the Main Menu: choose Scenario Analysis then click Quick Scenario Analysis with Tree. Use this feature to call up or to mix and match an extensive number of scenario interventions and/or a set of stored scenario intervention files, or to change any parameter or initial condition used in the software for any country/region, thus effecting the relationships used to forecast trends. Use the Quick Scenario Analysis with Tree to create Scenario-Load-Files (.sce), run these files through IFs in order to create Run-Result-Files (.run) that you can use throughout IFs.

An example of the Quick Scenario Guide page in IFs when first opened.

This page has a number of features and options to create, load, adjust, and run scenarios. These options and features include:

• Continue: Go back to the previous menu or to the Main Menu of IFs.
• Scenario Files:
  • Clear Tree: Clear any interventions currently loaded to the scenario tree.
  • Open: To load any set of saved or preloaded Scenario-Load-Files (.sce). Hover over folder names to get to the desired scenario to load then click on that scenario. The Open drop down is based upon the "Scenario" folder in the IFs file on the current device. Follow the same file path from the "Scenarios" folder to get to the desired scenario. The parameter tree will change corresponding to the conditions of the chosen scenario file.
  • Name and Save: Open a pop up to save a newly created scenario. The popup includes two fields to enter text into; type in the fields then click Save or Cancel. The two fields are:
    • File Name: Enter a name for the created scenario.
    • Folder Name: Enter a new or already used folder name within the "User Defined Scenarios" folder under the "Scenarios" folder of the IFs file on the current device, to save the newly created scenario to that location.
  • Export to IFs Standard CSV Format: Save a CSV version of the scenario to the same folder that the currently displayed scenario is stored in. For newly created scenarios click Name and Save first before clicking this option. CSV versions of scenarios can be easier to manage and understand, as all years and dimensions are aligned in their given title column, unlike Scenario-Load-Files (.sce) that are written as text.
  • Export Working File: Download a Scenario-Load-File (.sce) of the current scenario tree.
  • Import IFs Standard CSV Format files: If a scenario is saved using the IFs standard csv format (use Export to IFs Standard CSV Format for an example of the format) in a folder under the "Scenario" folder in IFs file on the current device, it will appear as an option to import. Follow the same file path from the "Scenario" folder and click on the desired scenario csv to import.
• Add Scenario Component: Similar to Open from the Scenario Files options. Layer multiple scenario files or interventions by clicking a different scenario once one has loaded.
• Run Scenario: Open the Run page for the current scenario in the scenario tree. Adjust the horizon and click Start Run.
• Delete Selection: When an intervention is displayed on the screen next to the scenario tree from either clicking on a parameter directly in the tree or from the Parameter Search option, click Delete to remove that intervention from the current scenario.
• Set Group or Country: Click Groups to make interventions for particular groups, or Countries for a particular country or countries. The current selection will have a checkmark next to it.
• Annotate Scenario: Click Annotate to open a description of the scenario interventions based on the current Scenario Tree. This is auto generated, but to edit the annotation click in the text box and change or add text as desired. Below the text box click Save to save edits, Clear to remove all text in the annotation, Help to open the corresponding page in the Pardee Wiki, or Exit to return to the Quick Scenario Analysis Tree.
• Parameter Search: Click Search to open the Parameter Search page to search and select specific parameters. The Parameter Search feature is described below.
• Help: Open the corresponding page in the Pardee Wiki.

Parameter Search

Use the Parameter Search feature to search and explore parameters, and choose parameters to adjust for scenario analysis. Use this feature with the Guide to Scenario Analysis in IFs to find the parameters most useful for the intended intervention or scenario goal. Type the desired parameter name in the search bar then click Search. Click on the parameter which will bring a few options described below. Click Load to select this parameter in the scenario tree, to adjust it for a scenario. Click Help to open the corresponding page in the Pardee Wiki, or Continue to go back to the previous menu or to the Main Menu of IFs.

An example of the Parameter Search option for tfrm.

The options once a parameter is clicked include:

• Define: See a brief definition of what the parameter is.
• Block Diagram (Pop-Up): This feature is not working....Bring up a help-file that shows a diagram that broadly explains how drivers interact for the area of inquiry (agriculture, economics, etc.). There normally is also textual explanation.
• Equations (Pop-Up): See the mathematical equations that are used to determine this parameter.

Using the Scenario Tree

The easiest way to create scenario interventions is to use the Guide to Scenario Analysis in IFs along with the Parameter Search option, but if desired use the Scenario Tree. Click on any of the categories in the Scenario Tree (ex. Technological change.) to open sub categories and eventually to open up a parameter choices box. Once this box appears to the right of the scenario tree with parameter names and descriptions, click on any parameter to reveal a few options.

An example of the scenario tree being used for Technological Change, Energy, and with the QEM parameter selected; shows the options that selecting a parameter will reveal.

Not all the options will be available or functioning for every parameter; the options include:

• Select: Choose the parameter in order to change it.
• Drivers: Click to see what variables are affecting the chosen parameter.
• Explain (Pop-Up): See a causal diagram and an explanation of what affects this parameter.
• View Equations (Pop-Up): See the mathematical equations that are used to determine this number.
• Define: See a brief definition of what the parameter is.

The Main Menu of Quick Scenario Analysis with Tree provides you with a tree on the left hand side of the screen. This tree represents all of the parameters and variables used in IFs. One way to find the parameter or variable you would like to change is to understand the general groupings of these categories. The first two options on the tree, Technological Change and Environmental Uncertainties, allow you to shape the intensity of technological growth and the intensity of various environmental trends. The third, fourth and fifth option on the tree, Households/Individuals, Governments/Social-Political Systems and Firms/Businesses, allow you to shape the parameters for the three main global actors. The final two options on the tree, Selected Initial Conditions and Relationship Parameters, allow you to change parameters at the onset of your run-file or the relationships between various parameters.

Another way for you to find the parameters you would like to change is by selecting the "Parameter Search" option on the top right of the toolbar. Clicking on this with bring up a window with a search box. For example, if you are looking to work with the malnourished children parameters, type in "malnourished" and hit enter. This will bring up any parameter with the word "malnourished" in its name. You can also search for the parameter or variable by its abbreviation.

Selecting this option will bring up a new window. From this window you can accomplish the following:

Type Variable Name: In the top box, type in a variable name and click Search. This will bring up any variable/parameter that has your search term in its name/definition.

Load: After you have located a variable/parameter you would like to see displayed, click Load.

Continue: Click here if you would like to return to the previous menu.

Define; Block Diagram; Equations; Linkages

Exploring and Changing Parameters

One of the key features of Quick Scenario Analysis with Tree is the ability to change specific variables and parameters.

The image below shows you what menu becomes available to you if you click on one specific parameter from the tree located on the left of the Main Menu of Quick Scenario Analysis with Tree. You are presented with five options: 1.) select the parameter in order to change it; 2.) click on drivers in order to see what variables are affecting what; 3.) click on explain to see a causal diagram and an explanation of what affects this parameter;4.) click on view equations to see the mathematical equations that are used to determine this number or; 5.) click on define to see a brief definition of what the parameter is.

Changing specific variables and parameters menu

Spend as much time as you would like exploring the drivers, equations, definitions and explanations of various parameters. For this exercise, select TFRM. You will be asked to select a country or group. You can toggle between countries and groups at the top of your program window. For this exercise, choose France.

Because you selected a multiplier, the base-case value is always "1"—the model uses multipliers to easily raise or lower base-case values of many variables, and the multipliers are always "1" in the base case, so that values are unchanged by them. A multiplier can be distinguished from a variable because the ending of most multiplier abbreviations is the letter "m". You could use the Fully Customize option to create any pattern of intervention over time you desire, and at some point you should explore its use. But for now select the High option above the graph and note the change in the figure. This option will phase in a higher fertility for France.

You may also want to more specifically customize the TFRM. This can be accomplished by changing the speed in which your increase or decrease in TFRM takes place (through the slide-down menu on the top right, "Shift Years:"). If you would like more control over your parameters, you can click on the Fully Customize button located below the graph. This will present you with a menu. This will allow you to very specifically change your parameters. Click on the Next Year or Previous Year options to see the numeric representation of how your parameter is being altered from the base-case. You can then choose what year you would like to specifically change, toggle to that year, change the value of that year by clicking on the box next to Desired Value. After you have entered your value, click on the Change/Repeat button to enter it into IFs. This change can then be interpolated for your remaining years by clicking on the Interpolate button. To apply your changes to IFs, click on Exit to Scenario Tree.

Multipliers, however, are not the only form of parameter in IFs. If you select a parameter located under the Selected Initial Conditions category, as the name suggests, you will be able to change initial conditions for certain parameters. For example, the HIV infection rate, initial percentage sub-sub-category (Selected Initial Conditions, Demographic – Mortality) will let you numerically alter the initial percentage of the population infected with HIV for your country or group.

If you choose other parameters, for example, the Carbon Tax (Governments/Socio-Political Systems, Environment), you will be presented with a parameter that numerically begins at zero. This is because there currently is no carbon tax in place. You may change the parameter to take into consideration a future world where carbon taxes are a reality.

Finally, if you choose a parameter in the Relationship Parameters category, you will be able to change the relationship between two different parameters. You may want to change the mathematical relationships in the "black-box".

If you have mistakenly changed a parameter and you would like to remove your alteration, simply click on the parameter change you would like to remove and then click on the Delete Selection option at the top of the menu. You will be asked whether you would really like to delete your parameter change. Click Yes.

Now you have changed a parameter, but it will affect nothing else until you run the model and recalculate all of the variables in it for all of the countries. You have created a Scenario-Load-File (.sce) and, in order to use it more broadly, you need a Run-Result-File (.run). Click on the Run Scenario option from the menu. Your parameter will first be loaded into the working file. You will then be shown the Running Scenario form. You can change the end year or leave it as is. Click on Start Run for IFs to create a new run-file based on your specifications.

After IFs has recomputed the model with your new parameters and saved it as a .run file, you will be presented with a screen that says, "Run Successful – Click to Continue." The run-file labeled "Working File" is now essentially your personalized scenario. Use the techniques you learned in the last section to compare the working file with the base case. But your intervention will have changed much else. Look, for instance, at Gross Domestic Product (GDP) of your country before and after the intervention and at GDP per capita (GDPPC). If your country or grouping was fairly large, you will see changes in many variables elsewhere around the world.

Now return to the Scenario Tree form and select the Scenario Files option, Name and Save sub-option. Give your scenario a name and the parameter intervention (but not the full results after your run) can be saved for you when you return to IFs later. If you are using the stand-alone (non-Web) version of IFs, the Scenario Analysis/File Management/Save option sequence also allows you to save all the computed results of the model run.