. 2021 Feb 24;9(1):8. doi: 10.1186/s40878-020-00210-4

Table 2.

Theoretical migration categories based on positive and negative liberty types

		Positive liberty (‘freedom to’; capabilities)
Negative liberty (‘freedom from’; external constraints)	Low	Precarious migration Generally short-distance, often internal, by relatively poor or impoverished people vulnerable to exploitation, i.e., poor rural-to-urban migrants, undocumented labour migrants, ‘failed’ asylum-seekers, internal displacees) (relevant theories: historical structural; dual labour-market)	Distress migration Deprivation of mobility freedom through absence of reasonable option to stay; applies to refugees fleeing potentially life-threatening conditions but possessing the resources to move abroad and obtain legal status (relevant theories: historical structural; network; new economics of labour migration)
High	Improvement migration Internal and international, often through networks, recruitment and pooling of family resources (relevant theories: new economics of labour migration; network and internal dynamics; cumulative causation; dual labour-market; mobility transition)	‘Free migration’ relatively unconstrained mobility in and between wealthy countries or by wealthy people, skilled workers, ‘lifestyle’ migrants (relevant theories: neo-classical; human capital; mobility transition)

Positive liberty
(‘freedom to’; capabilities)

Low

High

Negative liberty (‘freedom from’; external constraints)

Low

Precarious migration

Generally short-distance, often internal, by relatively poor or impoverished people vulnerable to exploitation, i.e., poor rural-to-urban migrants, undocumented labour migrants, ‘failed’ asylum-seekers, internal displacees) (relevant theories: historical structural; dual labour-market)

Distress migration

Deprivation of mobility freedom through absence of reasonable option to stay; applies to refugees fleeing potentially life-threatening conditions but possessing the resources to move abroad and obtain legal status (relevant theories: historical structural; network; new economics of labour migration)

High

Improvement migration

Internal and international, often through networks, recruitment and pooling of family resources (relevant theories: new economics of labour migration; network and internal dynamics; cumulative causation; dual labour-market; mobility transition)

‘Free migration’

relatively unconstrained mobility in and between wealthy countries or by wealthy people, skilled workers, ‘lifestyle’ migrants (relevant theories: neo-classical; human capital; mobility transition)