I came across with the word, “comparator” in the report of International Monetary Fund under the title, “Can women save Japan?” (WP/12/248) co-authored by Chad Steinberg and Masao Nakane
“Japan has FLP rates similar to comparator countries for women in their early twenties, but the participation rate drops off sharply for women in their late twenties and thirties.”

As I have never heard the word such as “comparator countries / territories/ companies,” I checked Google Search, and found out definitions;

●www.weblio.jp Computer /IT terminology Dictionary: Generic term of precision measurement. Comparative measurement devices that determine the length of the object by comparing measuring object and standard scale by using microscope.

●Wikipedia Free Encyclopedia (Electronics term)An element that can switch power output by comparing two different voltage or electric current. The word is also applied to the apparatus that compare two different data.

●dictionary.goo.ne.jp › A device designed for measuring minimum length with extreme precision. Comparative measurement instrument to determine the difference of the length of object and standard gauge by using high powered micro-scope.

●www.kab-studio.biz Interface for class comparison processing.

To me, none of the above definitions seems to be applicable to the quoted line, “Japan has FLP rates similar to comparator countries for women in their early twenties.”

At the same time, I don’t believe the writers of authritative organization like IMF makes misuse of word.

So, what does “comparator countries” mean? Does it mean the object countries of research, or simply the countries surveyed in this specific survey.?

Is it very common usage of the word “comparator” in comparative, or vital statistics, or even in daily conversation? If possible, I’d like to listen to the specific opinion from statistic specialists.