accounts, and report to and communicate with operational fieldworkers on projects. They are most often associated with the delivery of services or environmental issues, emergency relief, and public welfare. Operational NGOs may be subdivided into relief or development organizations, service-delivery or participatory, religious or secular, and public or private. Although operational NGOs may be community-based, many are national or international. The defining activity of an operational NGO is the implementation of projects. Advocacy Advocacy NGOs or campaigning NGOs seek to "achieve large-scale change promoted indirectly through the influence of the political system". They require an active, efficient group of professional members who can keep supporters informed and motivated. Campaigning NGOs must plan and host demonstrations and events which will attract media, their defining activity. Campaigning NGOs often deal with issues related to human rights, women's rights, and children's rights, and their primary purpose is to defend (or promote) a specific cause. Public relations Non-governmental organisations need healthy public relations in order to meet their goals, and use sophisticated public-relations campaigns to raise funds and deal with governments. Interest groups may be politically important, influencing social and political outcomes. A code of ethics was established in 2002 by the World Association of Non-Governmental Organizations. Structure Staffing Some NGOs rely on paid staff; others are based on volunteers. Although many NGOs use international staff in developing countries, others rely on local employees or volunteers. Foreign staff may satisfy a donor who wants to see the supported project managed by a person from an industrialized country. The expertise of these employees (or volunteers) may be counterbalanced by several factors: the cost of foreigners is typically higher, they have no grassroots connections in the country, and local expertise may be undervalued. By the end of 1995, Concern Worldwide (an international anti-poverty NGO) employed 174 foreigners and just over 5,000 local staff in Haiti and ten developing countries in Africa and Asia. On average, employees in NGOs earn 11-12% less compared to employees of for-profit organizations and government workers with the same number of qualifications . However, in many cases NGOs employees receive more fringe benefits. Funding NGOs are usually funded by donations, but some avoid formal funding and are run by volunteers. NGOs may have charitable status, or may be tax-exempt in recognition of their social purposes. Others may be fronts for political, religious, or other interests. Since the end of World War II,