Changing serialized migration parameters

Not every parameter can be changed after the creation of serialized files. The following overview is intended as high-level guidance for what changes can and cannot be made.


  • ON-to-OFF: If you turn it off, there will be no human migration even if the serialized file had trips planned or people were waiting to return.

  • OFF-to-ON:

    • If the file was serialized with migration off, and you set the Migration_Model to FIXED_RATE_MIGRATION and set Migration_Pattern to SINGLE_ROUND_TRIPS/RANDOM_WALK_DIFFUSION, then the migration will work as expected.

    • If the file was serialized with migration off, and you set Migration_Pattern = WAYPOINTS_HOME, then the serialized people will be fixed at one waypoint. Newborns will get the value of Roundtrip_Waypoints, but not the serialized people.


This cannot be serialized. Changing the value will change behavior but not in a guaranteed way. For example, if you change it from SINGLE_ROUND_TRIPS to WAYPOINTS_HOME, Roundtrip_Waypoints is always 1 for the people that were serialized. Newborns should get the new value.

Note that while the type of Migration_Pattern cannot be changed, other migration parameters can be changed under specific circumstances.

Migration_Pattern = SINGLE_ROUND_TRIPS

The following parameters can be changed as long as Migration_Pattern was serialized as SINGLE_ROUND_TRIPS. Changing this parameter will not impact those people who have determined their return trip before the file was serialized. After de-serializing, new decisions to return will use these parameters.

  • Air_Migration_Roundtrip_Probability

  • Family_Migration_Roundtrip_Probability

  • Local_Migration_Roundtrip_Probability

  • Regional_Migration_Roundtrip_Probability

  • Sea_Migration_Roundtrip_Probability

  • Air_Migration_Roundtrip_Duration

  • Family_Migration_Roundtrip_Duration

  • Local_Migration_Roundtrip_Duration

  • Regional_Migration_Roundtrip_Duration

  • Sea_Migration_Roundtrip_Duration


This includes the parameters Enable_Local_Migration, Enable_Region_Migration, Enable_Air_Migration, Enable_Sea_Migration, and Enable_Family_Migration.

  • ON-to-OFF: If Migration_Model = FIXED_RATE_MIGRATION and you turn these off, existing plans for migration - both out and return - will still occur. However, no new migration plans will be made.

  • OFF-to-ON: People should start migrating as designed.


This can be changed under certain circumstances. If you serialized with Migration_Pattern set to WAYPOINTS_HOME, you can change this but it will NOT change the number of waypoints for the people that were serialized. All the people being born after de-serializing will receive the new number of waypoints.