How to choose between 均衡 and 平衡

Question

Both 均衡{きんこう} and 平衡{へいこう} express equilibrium or balance. Both can be used with the verb 保{たも}つ.

When is one more appropriate than the other?

Answer 1

Semantically both are rather close. It is more collocations that distinguish them, so ultimately you have to learn when to use which phrase by phrase. For example, equilibrium in economics is usually 均衡 and equilibrium in physics is 平衡.

A possible guideline is that 均衡 is a balance of multiple entities and 平衡 is inner balance of a system. So the emphasis is on multiplicity of agents in economics and on the system as a whole in physics (and other natural sciences).

• 精神の平衡 : balance (peace) of mind Here mind is considered as a system.
• 勢力の均衡 : balance of power Meaning the balance (e.g.) among the nations.

I think practically 均衡 is more frequent unless you are a scientist.

Answer 2

'均衡' is the balance among two or more things.

'平衡' is the balance of statuses inside of one thing.

However, we use '均衡' in most cases. '平衡' is too technical.

Answer 3

I'm basing my answer on this thread: https://okwave.jp/qa/q4107038.html

均衡

Describes the balance between concrete entities. For example:

• 均衡財政 = Balanced finances (can be calculated by looking at income/expenditures, therefore it's concrete)
• 地域間の均衡ある発展 = Balanced development between regions (the development can be measured in terms of infrastructure etc, therefore it's concrete)

平衡

Describes the balance between abstract things such as gases or liquids. For example:

• 精神の平衡を保つ = Maintain the balance of one's mind
• 平衡熱 = Thermal equilibrium

Answer 4

均 divide .... equally
平 level; even; flat status of equilibrium

均衡 divide something equally, so as to weigh evenly.

平衡 already being status of equilibrium or even