States are grouping and regrouping amid arguments over representation and non-representation as the start of the G20 summit here looms.

However, for the existing groups in the world, like the Group of Twenty (G20), efficacy hardly prevails in problem-solving, except for one to some extent - the recent global financial difficulties.

Tiding over the hard times, states inside and outside the G20 are still fumbling for a "cure-all."

The core of this efficacy problem is that the members within the group weigh their respective individual interests above the so-called common interests or shared interests of their own group.

Thus, any concerted answers, not to mention common action, on regional or international economic problems is hard to achieve.

Working out development strategies for their own and their shared economic world, the G20 members also need to enhance their group's collective spirit and accountability in global economic governance.

Though the G20 already includes the world's largest economies from both the developed and developing world, more than 2 billion of the world's 7 billion people remain unrepresented.

Though it now accounts for almost 90 percent of the world's GDP, 80 percent of its trade and 70 percent of its population, it has been trying to include in its summitry such representations as the Business 20, Civil Society 20, Labor 20, Think Tank 20 and Youth 20.

However, these hardly have any real voice or substantial influence upon the group's decision-making.

G20 leaders have responded to criticism of their accountability by launching a mutual assessment process (MAP) as a platform for anti-crisis policy coordination, data exchange and sustainability analysis but the transparency of enforcement still makes a solution to the accountability issue elusive.

Even the G20 Financial Stability Board (FSB), formed to enhance coordination and set standards for financial regulation, has not helped much, as increased representation has caused decreased efficacy.

The G20 is becoming too diffuse to agree on concrete meaningful actions except in the event of a global crisis.

If the United Nations, which embraces 193 member states, is assumed to tackle the world's political issues, the G20, which actually comprises 43 countries, should concentrate more on economic and financial issues.

Yet, no economic or financial issues can be properly tackled without dealing with the political issues at hand, especially in a world where political, economic and military power still dictates who has the most say, like the United States, which holds sway over both the UN and G20.

So the mentality of the U.S. leaders should evolve to also care about others' interests, otherwise the American philosophy, as put by late U.S. diplomat Richard Holbrooke - multilateral when we can, unilateral when we must - will doom a group which should work multilaterally, consensually and collectively.