Reasons for Adopting the Federal System of Government: Size: A state is a large territory may adopt a federal system for administrative convenience.
Heterogeneity: A state may adopt federalism as a result of the diverse population with different languages and cultures.
Security consideration: A group of small states may unite to form a federal state for fear of an imagined or real enemy. An example of such state is Switzerland.
Economic reason: A group of autonomous states may adopt federalism in order to pool their resources together for mutual benefit.
Historical reason: Historical antecedents like colonialism, past trade ties may lead to a federation of hitherto autonomous state.
Geographical proximity: The desirability of states to form a federation depends on their geographical closeness to one another.