**1. Introduction**

Millions of people are continually forced to leave their home countries for various reasons. According to data from the UN Refugee Agency, UNHCR [1], in 2017, 68.5 million people were forced to flee their countries: of these, 4.4 million people emigrated to one of the EU-28 Member States [2]. It is estimated that a considerable number of them are people with disabilities, although very little information is available about them [3].

There are many reasons why people move to another country, sometimes voluntarily for professional or academic reasons, but there are many others who do so forced by a conflictive situation or catastrophe in their country of origin [4]. Similarly, there are many complexities involved in the phenomenon of migration, giving rise to what Vertovec defines as "superdiversity", understood as "a dynamic interplay of variables among an increased number of new, small and scattered, multiple-origin, transnationally connected, socio-economically differentiated and legally stratified immigrants" [5]. In other words, the term superdiversity indicates that not only are there differences between the people of the host country and citizens of other nationalities, but that there are also differences between all immigrants in terms of their multiple origins, their socioeconomic differences, and different languages, etc. Put another way, Vertovec points out that we are talking about a diversification of diversity.

The growing notoriety of these social issues in the international arena leads to questions about the interrelations that occur between migration and disability. In keeping with Crenshaw's [6] intersectionality theory, according to which each individual suffers oppression or holds privilege based on their membership in multiple social categories, if the population with disabilities and the migrant population are separately subject to political action because of the vulnerability of their situation, then being a migrant while having a disability must be approached through the interaction of the inequalities faced by the collective. Hence the need to study the characteristics of the migrant population with disabilities and the obstacles that must be overcome in different contexts so as to allow for the design of adequate planning to develop effective policies that address their needs [7].

It should be noted, as McAuliffe and Ruhs point out [8], that the International Organization for Migration recognizes disability as an element of vulnerability:

Vulnerable migrants are those who, even without meeting the requirements to receive protection under refugee frameworks, face a variety of situations in their home countries that endanger their lives or are subject to discrimination based on any reason (p. 159 [8]).

A politically effective response to the current migration crisis in Europe requires a greater understanding of the causes of migration. Inconsistencies in European statistics on irregular migration make this difficult. However, there are two key drivers for this phenomenon to occur. The first involves the combination of conflicts and political instability, and the second stems from the economic insecurity in the countries of origin, which seems to be the engine of migration [9].

Moreover, people seeking refuge in a foreign country often experience trauma and distress due to their uncertain residential and legal status. Previous research has identified how the relevant services and the creation of policies continue to be precarious in responding to their needs [10].

Under the generic paradigm of disability and immigration, it is necessary to understand common situations in which both realities are combined with everyday activities. Previous research has pointed out clarifying examples, such as the educational reality of migrant children with disabilities [11] or the employment situation [12]. All of them are necessary for a greater understanding of the phenomenon of migration and for improving the living conditions of migrants with disabilities.

The general objective of this study is to analyze the phenomenon of migration in Europe from the perspective of superdiversity, as well as the social responses that are currently offered through the action protocols in different host countries. In addition to this general objective, the following research questions are presented to provide a guide for the synthesis of information from the scientific literature:

**Research question 1:** Why is it necessary to speak of superdiversity in migratory movements today? **Research question 2:** What are the implications of dual vulnerability when the condition of being a migrant and having a disability intersect in an individual?

**Research question 3:** What action protocols are being carried out to improve the coexistence of migrants with functional diversity in host countries?

To respond to the proposed general objective and the different research questions, we provide a critical review and analysis of legal, political and human rights documents, methodologically approached using the causal inference model.

#### **2. Methodology**

A review of the literature was conducted in the Web of Science, Scopus, PsycINFO ProQuest and PubMed databases, in the Google Scholar academic search engine, international web pages related to the field of research, and Legislation and Jurisprudence Databases.

The methodology applied for the development of this legal and human rights policy document is based on the Frankfort–Nachmias and Nachmias model of causal inferences [13].

Among the main components of the inference model, it is necessary to point out the strength of the causal approaches, since in them lies the identification of the social mechanisms that will explain the relationship between a cause and its corresponding effect. Being able to discover what the mechanism is through research also facilitates an articulated reconstruction of events. All this leads to an explanatory–causal model. Consequently, different theoretical perspectives are selected, considering the following operational path in the research design (data → information → evidence), collecting and assembling the evidence with data and information.

The ultimate goal is to create a structure capable of providing a comprehensive political analysis of migration and disability in Europe that is able to assemble significant evidence and thus provide the opportunity to propose solutions or mitigate the negative consequences of this phenomenon.
