How people elect parliaments
Canada has a bicameral Parliament of which the lower house is the House of Commons or Chambre des communes, an assembly of 338 members following the 2015 election.
Each of the 10 Canadian provinces is allocated a number of seats determined by the population of the province at the preceding decennial national census (the most recent being that of 2011) divided by a predetermined quotient (which value was set at 111,166 for the 2014 redistribution, and is set to increase after each census according to a formula), rounded up.
Each province is then allocated additional seats to ensure that it has (1) at least as many members as it has national Senators (which numbers are specified for each province in the national Constitution), and (2) at least as many members as it had in the year 1985. These two rules have the practical effect of increasing the number of seats for the smaller provinces.
After adjusting province seat allocations to satisfy the above two rules, each province will be then be allocated the smallest number of additional seats necessary to ensure that the ratio of seats in each province to the total number of all province seats (as the total stood after the first two rules were applied) is equal or greater than the ratio of the population of that province to the total population of all the provinces (with all population values being those as at the preceding decennial census).
The third rule has the practical effect of increasing the allocations to the medium and larger sized provinces and bringing the whole allocation to all provinces into an approximately proportional final result.
The application of these three rules to the 2011 census population figures for each province yielded a total of 335 seats for the 2015 election. Finally, one further seat in the House is allocated to each of the three non-province Territories,bringing the total size of the House to 338.
After each census-based revision of the provincial seat allocations, an independent commission is established for each province to make any necessary revisions to riding boundaries. The process of redefining electoral boundaries is termed a redistribution.
The criteria for boundary revisions – defined in the Electoral Boundaries Readjustment Act – are based around population data, and aim to ensure that each riding in a province covers a population that is within 25% of the mean population for ridings across that province, unless there are exceptional circumstances relating to geographical, cultural and other communities of interest.
The results of each redistribution are recorded in a single national ‘representation order’, the most being the Representation Order of 2013, which sets out the result of the 2012-13 redistribution process.
Terms are nominally fixed at four years. The Canada Elections Act provides for each general election to be held on the third Monday of October in the fourth calendar year following the previous general election. The next statutory election date is October 21, 2019.
However the statutory provision, adopted in 2007, does not override the constitutional principle that the Governor-General can call an election early on the advice of the Prime Minister, as indeed occurred in calling elections in 2008 and then again in 2011.
Reform of the Canadian House of Commons electoral system (March 2017)
Inequality in the effective influence of voters caused by variations in House of Commons riding enrolments has been substantial in recent elections, with the standard deviation of variations compared to the mean enrolment being 22.3% in 2011.
[nomination openness – party configurations]
[summary of results]
Inequality in the effective influence of voters caused by variations in constituency turnouts (formal votes) has been significant in recent elections, with the standard deviation of variations compared to the mean formal vote being 24.3% in 2011.
[inequality by margins]
2011 – 2015
[data source – data completeness – anomalous contests – augmentation]
[Dataset not yet published]