Make Policy the Base

After you have run a Policy, you may wish to investigate other policies which start from this Policy. If so, you can click on this menu item (under the File menu) to ask RunDynam to make the current Policy into a new Base case.

If so, RunDynam

•changes the Sim Name for the Base to be the same as that of the Policy.

•sets up the Base Closure and Base Shocks columns on the Closure/Shocks page so that the results of the new Base will be exactly equal to the results of the former Policy.

•copies files and sets up Record of Runs files to that RunDynam thinks that you have already run this new Base case (even though you haven't actually run it and you don't need to run it). [If you ask RunDynam Where to Start ?, it should tell you that the Base case is all ok and that you need to start with the Rerun and Policy.]

Then you should set up the new Policy (change Sim Names for Rerun and Policy on the Sim Overview page and set up Policy Closures and Shocks on the Closure/Shocks page) and proceed to solve the Rerun and Policy sims.

Note that you must have all results (Base, Rerun, Policy) up-to-date before you ask RunDynam to make the Policy the Base. If, subsequently, you have second thoughts about the original Base and Policy, you need to get up-to-date results for those and then do Make Policy the Base again and then, if necessary, rerun any Policies based on this converted Base.

RunDynam does not change the starting year or starting data. If the old Policy starts say in the third period, the first two periods of the new Base will be the same as the old Base and the subsequent periods of the new Base will look like the corresponding periods of the old Policy. If you want the new Base to start later (perhaps when the old Policy started), you can Omit Some Periods at the Start.

Not always possible

In some models, the policy simulation reads updated data files that are created in base or rerun simulations. This behaviour is specified in the DIN file. For such models, you are not allowed to 'make policy the base'.

All files used in the Base simulation must be either (a) initial data files listed on the Model/Data page, or (b) updated files created during previous periods of the Base simulation. RunDynam does not have a mechanism which allows the user to specify, in the Base simulation, that updated data files be read from a non-Base sequence of files.

Prior to July 2015, RunDynam DID NOT prevent users from 'making policy the base' in the circumstances described above. In that case, if the new Base Simulation were run again, results are likely to differ from those generated during the former Policy simulation.

URL of this topic: www.copsmodels.com/webhelp/rundynam/hc_poltobase.htm

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