How can we quantify the power of a country? Putting so many demographic, economic and military factors into a single number may seem like a daunting task, full over oversimplification and abstraction. Fortunately, an entire field exists exclusively to oversimplify and quantify the unquantifiable. I am speaking, of course, of statistics.

Probably the most influential method of measuring national strength (aside from basic numbers like GDP) is through CINC scores. CINC (short for Composite Index of National Capabilities) is a system created by statisticians in 1963 to boil down the economic and military strength of a country into a single number. The way it works is by combining six variables:

• Population 
• Urban population
• Iron and Steel Production
• Energy Consumption
• Military Expenditure 
• Military Personnel 

Each of these six figures is compared with the world total to create a ratio, and the ratios are combined to determine the CINC score. Thus, a country like China has a CINC score of 0.22, meaning that China possesses roughly 22% of the world’s total military/economic power.

How good of a metric is CINC? Not a very good one, I would argue. For one, its variables are outdated. After all, the factors that make a country powerful do not remain constant over time. Iron and steel production, for example, was a vital sign of industrialization back in the days of the World Wars, but it is nowadays often seen as less significant.

How can we assess the accuracy and usefulness of CINC scores? Fortunately, statisticians are nothing if not thorough, and the Correlates of War Project (the group to invent the CINC score) has gone back into history and determined various countries’ CINC scores almost 200 years back. We can, for example, know the CINC score of the United States in 1819, or of China in 1860. 

With this information, we are able to look back and see how CINC scores have played out in history. In particular, we need to ask ourselves two simple questions: how reliable is CINC as an indicator of short-term strength, and how reliable is it as an indicator of long-term strength? 

how well does cinc measure short-term power?

Broadly speaking, states how two kinds of power: short-term power, which indicates a state’s ability to achieve a particular goal with he resources directly at hand, and long-term power (also called latent power), the ability to increase its own resources to meet future challenges. A country with a huge military but a weak economy has a lot of short-term power, but little latent power, since its expensive military has no foundation to maintain it in the long term.

To determine how well CINC scores measure short-term power, we must look at the clearest metric of a state’s short-term power: warfare.

I used CINC scores to examine a number of wars over the past 200 years. To maximize accuracy, I only used conflicts between two countries where neither side received substantial foreign aid, and the conflicts were large-scale and lengthy enough to cause both countries to utilize the full extent of their capabilities. 

So how does the CINC score fare in this sort of analysis? Not particularly well. Most of the times CINC correctly predicts the outcome of the war, the comparative forces are extremely lopsided. It is not a very impressive feat, for example, to correctly predict the outcome of the 1939-1940 Soviet-Finnish war, when the Soviet Union’s CINC score was, at the time, 69 times higher than that of Finland. Similarly, CINC doesn’t score many points when it predicts that the US was going to win the Mexican-American War (the US had a CINC score 10x that of Mexico). 

The CINC score frequently fails to predict outcomes, often dramatically. In the 1894 Sino-Japanese war, for example, the Chinese enjoyed a CINC score five times higher than the Japanese, but in reality, the Japanese mopped the floor with the Chinese.

Other upsets also occurred. In the Chaco War, fought from 1932-1935 between Bolivia and Paraguay, Bolivia enjoyed a CINC score double that of Paraguay, yet after a grueling three-year conflict, the Paraguayans came out victorious. Also, during the 1870-1871 Franco-Prussian War, the French enjoyed the clear edge, with a 15% higher CINC score, but in reality it was soon Prussian grenadiers who marched through the streets of Paris. 

China is in many ways the poster-boy for CINC’s problems. For much of the 19th and 20th centuries, China possessed a very large population and economic potential (in other words, lots of latent power), but a very weak military. Large population is not useful in the short term, especially in a military context, because a population needs to have equipment and training in order to have any military or industrial use. 

As a result China’s CINC scores have tended to dramatically overestimate the country’s short-term military power.

According to CINC, China surpassed the US to became the world’s most powerful country in 1995. While it is certainly valid to believe that China may soon eclipse the United States, no one could possibly claim that such an event occurred in the 1990s, when the United States dominated international affairs and was the world’s unquestioned sole superpower. China surpassed the US in 1995 because CINC’s long-term factors, not its short-term ones.

The reason for CINC’s spotty record of predicting warfare is largely that warfare is concerned with a lot of relatively short-term factors like quality of military commanders, training of soldiers, equipment of troops, efficiency of political system, and the like. Many of these factors are both difficult to quantify and can change rapidly over time. Therefore, CINC scores are not very effective at measuring short-term power.

CINC as a long-term metric

Clearly, CINC scores are not a particularly accurate measure of short-term power. But perhaps it does a better job of determining long-term power? Not really. 

If you look at the above chart, you will see that CINC scores shift dramatically in the short term. During the Civil War, First World War, and Second World War, the United States’s CINC score skyrocketed, as America industrialized and raised huge armies. Between 1940 and 1944, for instance, American military personnel numbers increased by a factor of 25, causing an enormous spike in CINC score. This sort of thing shouldn’t happen in a long-term metric. If a country’s CINC score can change dramatically at the drop of a hat, what use is a CINC score? Shouldn’t a CINC score take into account potential military power as well as deployed military power?

In my view, the central problem of the CINC score is that it combines short-term factors (like military expenditure and military personnel) with long-term factors (like energy consumption and population). As a result, it is neither very good at assessing short term factors (like the probable winner in a war) nor at assessing long-term factors (like a country’s economic and industrial potential). 

Ultimately, it is not useful to use a single number to determine national power or capability unless “capability” is rigorously defined. Since long-term capability and short-term capability stem from such different variables, I would propose using different scores to assess each one. This will have the added benefit of offering a more nuanced version of historical power. That way, China in the 19th century can be both militarily weak but with great economic potential. 

While on the subject of ways to improve CINC, the long-term and short-term variables themselves could use some modernizing. Technologies such as cyber capabilities and artificial intelligence might be as important as steel production in modern economies and militaries, so a variable to represent technological development would be a good addition to the short-term CINC score. Similarly, for the long-term CINC score, why count the entire population, instead of counting population of a working age, say, 18-50? Counting only young and productive adults would represent the fact that countries with younger workforces have better long-term prospects than countries like Japan with a rapidly approaching population bomb. The variable adjustment would introduce the idea of demographic decline to CINC scores, and add a vital long-term factor to national success.

Such modernized CINC factors would be hard to apply to history, but that is probably for the best. We should really abandon the idea of applying CINC scores to history. As fun as it is to compare Prussian and French capabilities during the 1870 Franco-Prussian War, we must remember that the factors making a nation powerful change overtime, so using a fixed formula designed for modern countries does not apply to historical scenarios. Ultimately, in the search for the root of state power, the past can only tell us so much.