“All citizens of all countries desire to be governed well.”

That plain statement — universal and self-evident — is the first sentence of a Harvard-generated report released this week in London. According to its authors, it is the first attempt in the world to systematically and objectively quantify governance.

Governance is the performance of government, measured by the way leaders and institutions deliver essential services. It is also the complex interaction between a government and its citizens regarding “political goods” like safety, health, human rights, adequate roads, and drinkable water.

“Strengthening African Governance: Ibrahim Index of African Governance,” with 352 pages of tables and text, ranks the quality of governance in the 48 countries of sub-Saharan Africa. Scores are on a scale of 100 to zero, and use five basic indices of governance: security, the rule of law, human rights, economic opportunity, and human development.

Embedded in each category are 15 subcategories and 58 sub-subcategories of numerical data, spelled out in more than 100 Excel spreadsheets.

“Proxy indicators” — complex arrays of quantifiable data — provide indirect but reliable measures of how well security and other political goods are delivered. For example, the apparently subjective category of “human development” is quantified in part by dozens of assembled data sets, from infant mortality rates to the number of physicians per thousand citizens.

A series of “special papers” included in the index spell out methods, definitions, and categories.

The index “is enormously complex, and enormously rich in terms of data,” said principal author Robert I. Rotberg. He’s adjunct professor of public policy at the John F. Kennedy School of Government and director of the Belfer Center’s Program on Intrastate Conflict and Conflict Resolution.

Detailed report cards on credit ratings already exist for nations, and they influence financial decision making, he argues. Why not develop a comprehensive, quantifiable universal rating system for governance?

Starting in 1998, Kennedy School students under Rotberg’s direction started to formulate a variety of proxy indicators in order to indirectly but robustly measure governance. Since then, the senior scholar has floated the idea of a governance index in a series of articles, policy papers, and conference presentations.

In 2004, he co-wrote a World Peace Foundation working paper titled “The Good Governance Problem: Doing Something About It.” An index “will compel countries to recognize that governance counts,” he wrote, “that good governance is measurable and bad governments can no longer hide.”

In an essay in The Washington Quarterly two years ago, Rotberg said that strengthening governance in developing countries is “an urgent task” in an age of terror. Three-fifths of the world’s population lives in the developing world, he wrote — and “the vast majority” of them are poorly governed.

Such an index would not measure a nation’s intentions, but its outcomes. It would not measure how much money is in a national budget for roads, for instance, but how many miles of roads were actually built.

The present index — with separate data tables and rankings based on 2000, 2002, and 2005 data — builds on the work of the former students. It was finished earlier this year by a staff of 10 part-time research assistants from Harvard’s Schools of government and law.

“It was nice to have so many students,” said project research associate and political scientist Rachel M. Gisselquist, an Africa specialist at the Kennedy School. “It’s fantastically difficult to get good data on developing countries, especially in sub-Saharan Africa.”

There are already as many as 100 international compilations of data that rate nation-states, but Rotberg called them “partial schemes” that measure only “slivers” of governance.

Transparency International, for instance, publishes an index cataloging corruption. Freedom House lists countries that are not free or only partially free. The United Nations Development Program has a human development index that looks at a nation’s attainments in health, education, and income.

Most of these compilations also avoid explicit rankings, said Rotberg. Many are based on subjective measures, he said, chiefly —“our only competition” — the World Bank’s Worldwide Governance Indicators, a 1996-2006 compilation of research on 212 countries.

“Governance is not some aesthetic, or some anecdotal or impressionistic view, as some seem to think,” said Rotberg, who has written prolifically on failed states, rogue leaders, and Africa’s civil strife. “It’s not a style. Governance is something capable of being measured quantitatively — otherwise it doesn’t have any meaning.”

In the index rankings for all three years of data, a select few of the African countries consistently come out on top, including Mauritius, the Seychelles, Cape Verde, Botswana, and South Africa.

The worst performers — including Chad, Sudan, and the Democratic Republic of Congo — showed the same consistency by filling out the index’s bottom ranks in all three years.

Based on 2005 data, Mauritius earned the index’s highest score for governance, with a grade of 86.2. The island nation off the southeastern coast of Africa has a stable parliamentary democracy, regular elections, and one of the continent’s highest per capita incomes.

In the same table, Somalia earned the lowest score, 28.1, including an abysmal grade of 5.1 in the category that measures sustainable economic opportunity. Somalia is beset by anarchy and factional fighting, and has had no real central government since civil war broke out in 1991. As many as 1 million Somalis have died in the fighting, from starvation, or from natural disasters.

“My motive is not to rank for the sake of ranking, but to make African lives better,” said Rotberg, a long-time Africanist who is also president of the World Peace Foundation. He envisions the index as a reliable diagnostic tool — a comparative measure that can be used by African nations and their citizens, as well as donor groups, scholars, and foreign investors.

The index is supported by a grant from the Mo Ibrahim Foundation, and will be published annually for at least a decade — long enough for statistical patterns to emerge. “Longitudinal data is critical,” said Rotberg.

Most of the numbers used in the index come from standard international sources such as the World Health Organization and the World Bank. But Harvard will supplement those sources by going into the field to collect its own data starting this year.

“We have to be suspicious, and we have to double-check it,” said Rotberg of the index’s underlying data — which he said rely largely on “insufficient” international records, and “poor statistical services in Africa.”

“Aren’t all data problematical?” Rotberg asked. “But I’m keen on measuring as much stuff as can be measured.”

Gisselquist said the Harvard team is braced for criticism, and welcomes it as a way to check and improve the index, its data, and its methods.

There will be some reaction to the way the Harvard group defines governance and the political goods that underpin it, she said — and some critics “are more interested in perceptions of governance” than in hard data. Others are bound to question the rankings of specific countries.

“We’ll double-check our premises and sources, and we’ll listen to the critics,” said Rotberg.

The focus for now is on Africa because Ibrahim is an African, said Rotberg. But the index’s analytical scheme can be used to measure the efficacy of governance anywhere — “in Boston, Cambridge, New Jersey, any place in the world,” he said.

The index, available online, will also be released in book form within three or four weeks.