Table 2 Key dimensions of solidarity analysed in the study

Democracy

The participation of all organization members in governance and decision-making processes is considered as organizational democracy [16, 32]. Democracy is a relevant variable because it influences economic development and social improvements. Democracy protects the rights and freedoms of citizens [19] and promotes inclusive institutions [17]. Thus, citizens can express their voice [18], making their organizations, governments and States more successful.

Pluralism/ Diversity

In terms of the members making up an organization, cultural, ideological, religious and other identity diversities are considered as a competitive advantage [22]. Diversity, together with democratic decision-making processes, enriches the organization, accumulating more social capital and consequently, more effective and successful actions [23]. Thus, some scholars [21, 33] have noted that plurality should be recognised and promoted.

Transparency/ Accountability

Transparency in NGOs has acquired a prominent role in recent years, especially after the economic crisis and specifically for NGOs which are working to reduce inequalities and respond to social needs [25, 34]. These entities are mainly financed through donations from individuals [27, 35, 36], and society is interested in how the funding is used and the actions that these organizations carry out [26, 37, 38]. So, transparency acts as a mechanism of institutional legitimacy, increasing the donors´ trust and thus the ability to continue doing their work.

Recognition

The social recognition of an NGO, such as having received an award, allows to have even greater social visibility and provides powerful incentives to continue their work [28], enabling them to generate a remarkable political impact.

Social and political impact

In the case of NGOs, showing their achievements is the first step to providing organizations´ legitimacy, resulting in performance legitimacy [30]. Social organizations and initiatives are increasingly required to demonstrate that they are improving the lives of the vulnerable groups they serve. Accordingly, social impact is understood as “the social improvements achieved as a consequence of implementing a particular project or action” [31] and “political impact as the institutional repercussions of this project or action”.

Scalability

To address the spatial dimension, we will look at the scope of the organization analysed, as well as the extent of the solidarity action. The relationship between success (in terms of social improvement of peoples’ lives) and scalability should be addressed.