Non-governmental organizations (NGOs) are becoming major actors in development cooperation: they have increased both in number and in size in the last decades. The share of public aid channelled through NGOs has increased, and the role of charities and so called private aid is even larger and faster-growing. Outside the developing world, NGOs, social enterprises and the other actors that exist in-between public and private sector are also gaining increasing importance in areas such as public health, education, social inequality, and environmental pollution. Public and private initiatives increasingly recognize them as a means of addressing a wide range of social needs, and seek to encourage and support them.