Demerger

Simple De-merger

Definition

The re-establishment of one municipality that had previously participated in a merger (either simple or multiple) into a new, separate municipality whose territory exactly matches its original boundaries prior to the merger, thereby fully reversing the territorial effects of its inclusion in that merger.

Implication of the change

Even before (year t-1):

• Municipalities A (with id 1¹), B (with id 2), C (with id 3), and D (with id 4) exist as separate entities, each with its own name, id, and territory.

Before (year t):

• Municipalities A, B, C, and D were dissolved.
• Municipality E was created, covering the combined territory of Municipalities A, B, C and D.
• Municipality E either retains one predecessor’s name/id or receives a new name/id.

After (year t + 1):

• Municipality C was re-established as a new, separate municipality whose territory exactly matches its original boundaries prior to the merger (year t - 1)
• Municipality E, from (year t + 1), combines only territories of Municipalities A, B and D.

Visual overview

The number of municipal units involved is indicated in brackets under each description.

Example

From 2019, the new municipality (commune in France) Les Hauts-Talican (id 60054) was formed by the merger of the municipalities Beaumont-les-Nonains (id 60054), Neuville-Garnier (id 60455), and Villotran (id 60694). The name was new, and the id was inherited from Beaumont-les-Nonains. However, from 2024, the municipality Beaumont-lès-Nonains is re-established as a new, separate municipality whose territory exactly matches its original boundaries prior to the merger. It reverts to its previous name, Beaumont-les-Nonains, and resumes the id 60054. The municipality Les Hauts-Talican, now consisting only of the former municipalities Neuville-Garnier and Villotran (from year t + 1), conserves the name Les Hauts-Talican but adopts a new id, 60694, inherited from Villotran. The case was registered in the metadata dataset under the id: fr-dm-1-2019-2024.

Plots

Before

After

After

Multiple De-merger

Definition

The re-establishment of more than one municipality that had previously participated in a merger (either simple or multiple) into a new, separate municipalities whose territories exactly match their original boundaries prior to the merger, thereby fully reversing the territorial effects of its inclusion in that merger.

Implication of the change

Even before (year t-1):

• Municipalities A (with id 1), B (with id 2), C (with id 3), and D (with id 4) exist as separate entities, each with its own name, id, and territory.

Before (year t):

• Municipalities A, B, C, D were dissolved.
• Municipality E was created, covering the combined territory of Municipalities A, B, C and D.
• Municipality E either retains one predecessor’s name/od or receives a new name/id.

After (year t + 1):

• Municipalities A and C were re-established as new, separate municipalities whose territory exactly match their original boundaries prior to the merger (year t - 1)
• Municipality E, from (year t + 1), combines only territories of Municipalities B and D.

Visual overview

The number of municipal units involved is indicated in brackets under each description.

Example

Since 2016, the new municipality (commune in France) L'Essarts-en-Bocage (id 85084) was formed by the merger of the municipalities Les Essarts (id 85084), Le Boulogne (id 85030), L'Oie (id 85165), and Sainte-Florence (id 85212). The name was new, and the id was inherited from Les Essarts. However, since 2024, two municipalities — (1) L'Oie and (2) Sainte-Florence — are re-established as new, separate municipalities whose territories exactly match their original boundaries prior to the merger. They revert to their previous names and ids. The municipality L'Essarts-en-Bocage, now consisting only of the former municipalities Les Essarts and Le Boulogne (from year t + 1), retains the name L'Essarts-en-Bocage and the id 85084, inherited originally from Les Essarts. The case was registered in the metadata dataset under: fr-dm-2-2016-2024

Plots

Before

Merger

After

References

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1. By id we mean code identifier of the municipality. ↩