Centralization

I think NofarLapidot offered a clear and helpful answer to the question. To add a little more, there exist some nations in which the process of centralization is not as visible and/or emphasized as that in the United States of Canada--for an example, South Korea, Japan, etc. Generally, countries composed of smaller geographical area and lesser states/provinces may not be used as prominent examples of centralization as there would be less to centralize--due to the already similar and initially centralized and/or similar system and ideals between different state/provincial governments.

I would argue that almost all nation states have a centralized government. To say that Canada and the United States are prime examples of centralization is valid, however South Korea and Japan have a prominent centralized government as well. Any developed countries or nation-states I would reason have some sort of centralized government, albeit in our Western society we tend to focus more on Canada and the United States. The idea of centralization in todays society tends to lean towards a possibility of economic success, and the developed countries are examples of this "success" by centralization.