Try, "Who makes that decision ... ? It's grammatical.
Each country makes its own decision as to how "socialist" their system is, exactly in what ways and how far the government may involve itself in the economy. Canada isn't a Republic, it still acknowledges in a lackadaisical fashion the primacy of the Queen through her representative the Governor General. Both those posts are entirely figure-heads. I could write you a very good post on why Canada is the way it is, and why Government involvement has always been a factor, but briefly it is because Canada was a vast tract of land with a very small population in 1867 when it achieved Independence, and was bounded to the south and north-west by an aggressive, greedy, and untrustworthy neighbour called the United States who had already invaded once. Consequently the newly formed government had to do a lot more than other governments had to do simply to ensure the survival of the new nation. The last invasion from the United States happened with the Fenian Raids of 1854 assuming I got the date right.
Now you could read any Canadian history and find this out. I don't know whether it is covered in sufficient clarity anywhere on Wikipedia, but it may be and certainly the Fenian Raids are likely to be. Nobody here blames the US for the Fenian Raids, but that doesn't mean that the early government of Canada (or current ones for that matter) was ignorant of or complacent about the dangers the US posed to Canadian survival and sovereignty. And you continue to provoke with for example the unauthorized passage of an icebreaking tanker through the North West Passage sometime in the last 25 years. It violated Canadian territory and territorial waters which encompass all the Islands and waterways, kind of like a Cuban ship deciding to sail up the Mississippi.
Canada and most of the countries in Europe are examples of limited Socialism.
As much as being a Republic is thought in the US as a purely American thing, it was the system of the Greek City States, and of Rome until the time of Caesar's Dictatorship, somewhere around 45 BCE. We didn't invent it, or the idea, but we did do it better than anyone else, until recently.
Being a Republic means that we have an elected government and an elected Head of State, just like La Republique Francaise. Don't you know what a Republic is? It isn't some strange divine and purely American thing, there are lots of Republics around. Germany is one, The Czech Republic is one, The Republic of Slovakia is one, the Republc of Ireland is one. La Republica Italiana is also one, and there are dozens more.
"A little learning" while sometimes dangerous, is still better than ignorance.
Rob