手法を比較

	Diaspora Engagement Mapping	Chain Migration Mapping
分野	Migration Studies	Migration Studies
系統	Process / pipeline	Process / pipeline
提唱年	2014	1964
提唱者	Alan Gamlen	John S. MacDonald & Leatrice D. MacDonald; Douglas S. Massey
種類	Inventory-and-classification pipeline for state diaspora policy	Network-tracing pipeline for serial sponsored migration
原典	Gamlen, A. (2014). Diaspora Institutions and Diaspora Governance. International Migration Review, 48(s1), S180-S217.	MacDonald, J. S., & MacDonald, L. D. (1964). Chain Migration, Ethnic Neighborhood Formation and Social Networks. The Milbank Memorial Fund Quarterly, 42(1), 82-97.
別名	Diaspora Institution Inventory, Emigrant Engagement Policy Mapping, Diaspora Governance Mapping, Origin-State Diaspora Policy Audit	Chain Migration Analysis, Kin and Paesani Chain Tracing, Serial Migration Mapping, Sponsorship Chain Reconstruction
関連	3	3
概要	Diaspora engagement mapping is a systematic method for inventorying the institutions and policies through which states reach out to, claim, and govern their populations abroad. Alan Gamlen's 2014 work on diaspora institutions and diaspora governance showed that since the 1990s a striking number of states have created dedicated ministries, offices, councils, and programs aimed at emigrants and their descendants, turning the diaspora into an object of deliberate statecraft. The method catalogues these bodies and classifies what they do, distinguishing capacity-building (cultivating a diaspora identity and the institutions to reach it), extending rights (offering citizenship, voting, and protections abroad), and extracting obligations (mobilizing remittances, investment, lobbying, and taxes). By coding which instruments each state deploys and how they change over time, the analyst maps the evolving web of ties binding origin states to their emigrants. The product is both a descriptive atlas of who is governed how and an analytic tool for comparing diaspora-engagement strategies across countries and explaining why they spread.	Chain migration mapping reconstructs the social mechanism by which one migrant's move triggers many others, tracing the kin, friend, and paesani ties along which earlier arrivals recruit and sponsor later ones into the same destination. John and Leatrice MacDonald's 1964 study of Italian migration to the United States gave the process its classic name, showing how chains of personal sponsorship channel newcomers into specific neighborhoods and produce the dense ethnic enclaves that dot immigrant cities. The method treats migration not as independent decisions by isolated individuals but as a self-feeding network in which each settler lowers the cost and risk of moving for those still at home. Douglas Massey's 1990 theory of cumulative causation formalized why such chains accelerate over time, as every new migrant expands the web of contacts that makes the next move easier. Mapping a chain therefore means building the directed sponsorship graph, ordering it by arrival time, and clustering it at the destination to reveal how neighborhoods crystallize. The result is both a descriptive map of who brought whom and an explanatory account of why migration streams persist and concentrate.