quality:correction, structural:summarization
Member country data

In addition to these 21 members, the chief executive officers of several other international forums and institutions participate in meetings of the G20. These include the managing director and Chairman of the International Monetary Fund, the President of the World Bank, the International Monetary and Financial Committee and the Chairman of the Development Assistance Committee.

The G20's membership does not reflect exactly the 21 largest economies of the world in any given year; as the organization states:

In a forum such as the G20, it is particularly important for the number of countries involved to be restricted and fixed to ensure the effectiveness and continuity of its activity. There are no formal criteria for G20 membership and the composition of the group has remained unchanged since it was established. Because of the objectives of the G20, it was considered important that countries and regions of systemic significance for the international financial system be included. Aspects such as geographical balance and population representation also played a major part.