The short answer to the question is "tradition". For a slightly longer answer, read on.
In Canada, as is also the case in America and Australia, coinage and banknotes are issued under two different authorities, with different laws regulating their issue. In Canada, the relevant law for coinage design is the
Royal Canadian Mint Act, of which Section 6.5 states "The Governor in Council may determine the design of any circulation coin to be issued.". In other words, the Canadian government has to formally pass legislation to change the coinage designs. I believe the Mint has a standing policy that the Queen's portrait is to always appear on the obverse of all coins, unless specifically requested otherwise.
I don't know about Canada, but here in Australia (where the laws are similar), all attempts to pass laws stripping the Queen off the coinage are usually met with cries of "Republicanism by stealth" from pro-monarchist politicians, so any such law changes are unlikely to be passed until and unless we actually become a Republic.
Banknotes are issued by the Bank of Canada and their design is governed by the
Bank of Canada Act, specifically section 25.4: "The form and material of the notes of the Bank shall be subject to approval by the Minister, but each note shall be printed in both the English and French languages." In other words, the Canadian Minister of Finance has the power to unilaterally approve of changes to banknote design which the Bank itself recommends. So changing the banknote design is less politically challenging.
In the case of note issue, there is a good case to not have the same portrait on every note: it minimizes confusion. In dim light or for the visually impaired/colourblind, notes that are the same size with the same portraits but different colours could be (and in the past often were) easily confused. There's also the security aspect: with identical portraits, on identical-sized notes, a counterfeiter could easily make a note resemble a note of higher denomination simply by judicious application of chemicals. Now, they could make half a dozen different portraits of the Queen, one for each denomination, but it would be even less confusing (and potentially fraudulent) if each note has a completely different person on it. I'm sure this line of reasoning is what the Bank argued back when the Queen was stripped off most of the denominations back in the 70s.
Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
Posted 02/23/2016 1:03 pm
