Less attention has been paid by researchers to the conceptualization and analysis of policies regarding irregular migration, expulsion and return of migrants.  Three are the main aspects addressed in the area of irregular migration and expulsion of migrants, which are the sanctions for irregularity, grounds for expulsion and formal mechanisms for regularisation of irregular migrants.  In this area, the main indexes to be taken in consideration are:

• The Index of Citizenship Rights for Immigrants (ICRI), which addresses the trade-off between the recognition of individual equality and of cultural differences by nation-states to immigrants.  Rights in 8 thematic fields are considered, meaning acquisition, family reunification, expulsion, anti-discrimination, public sector employment, political rights, cultural rights in education, and other cultural and religious rights. 
• The Nationalist Immigration and Integration Policy (NIIP) index, which covers several aspects linked to irregular migrants and expulsion. The index attempts to assess whether the integration and immigration policies developed by 9 countries under study had a clear right-wing orientation. The policy considered addressed areas such as citizenship, asylum, illegal residence/ regularisation, family reunion and civic integration. 
• Peters’ set of indicators, which provides a contribution to the study of expulsion policies by addressing the administrative/judicial process, including safeguard criteria and checks.  Peters conceptualised a set of indicators on immigration policies, covering 19 countries from the late 18th century through the early 21st century. The author identified three main policy areas including policies that regulate who gains entry to the state (border regulations), what rights immigrants receive (immigrant rights) and how the border is enforced (enforcement).

On voluntary returns, existing indexes cover the extent to which policies facilitate the return of migrants to their country of origin. Among others, we can list:

• The Dashboard of indicators for measuring policy and institutional coherence for migration and development (PICMD), which is a user-friendly tool that aims to benchmark current policy against international best practices, in order to minimize the risks and maximise the gain from migration. Among other elements, it addresses also policies promoting reintegration of emigrants (programmes, funding, benefits). 
• The Emigrant Policies Index (EMIX), which analyses the presence of return programmes – including benefits for returnees (e.g., recognition of academic qualifications, tax exemption) – and integration programmes for them. EMIX focuses on emigration policies in developing countries and it analyses the policies of 22 Latin American and Caribbean countries concerning emigration. It includes information about 102 policy indicators, divided in 12 dimensions and two components, namely policies and the administration setting developed to cope with their design and implementation.
• The United Nations Inquiry among Governments on Population and Development, which ncludes indicators on return policies for citizens living abroad and for migrants in the country of destination who want to come back to their countries of origin.