Bicameralism - pro and con
A bicameral legislature is a legislature with two houses or chambers, such as the Parliament of the United Kingdom (composed of the House of Commons and the House of Lords) or the Congress of the United States (composed of the House of Representatives and the Senate). The two houses or chambers, variously named in different national legislatures, are often distinguished as the lower house (or chamber) and the upper house (or chamber).
There are many differences of detail between bicameral legislatures – e.g., in the nature of each chamber (its size, the composition of its membership, etc.) and in the relationship between the two chambers (see further Senate (Contemporary) and below). However, irrespective of these differences, it is clear that, in principle, a bicameral legislature is better than a unicameral legislature in one respect but worse in another: it is an advantage of a bicameral system that, other things being equal, it subjects proposed legislation to greater scrutiny than a unicameral system, and it is a disadvantage that it makes the legislative process slower. The distinctive features of a particular bicameral legislature may enhance or reduce this advantage and mitigate or exacerbate this disadvantage.
Greater legislative scrutiny
In a bicameral system proposed legislation is subject to scrutiny by two bodies. This is clearly advantageous, since the greater the scrutiny to which a proposed law is subject, the more likely it is that any flaws in it will be discovered and possible improvements become apparent: two pairs of eyes are always better than one. However, many national legislatures enhance the value of scrutiny in a second chamber by having membership of this chamber determined in a different way from membership of the first (e.g., by appointment rather than election), the rationale being that the second chamber may consider proposed legislation from a different point of view and give weight to legitimate interests or concerns which the first chamber has failed to consider. This rationale may be elaborated in various ways.
Experience and expertise
Such restrictions as there may be on eligibility for membership of the lower house typically do little to ensure that its members are well qualified by character and intellect to act as legislators. By contrast, members of the upper house tend to be older than members of the lower house – for some information about age limits for membership of each house see Senate – and have often had successful careers and attained eminence outside the world of politics or been members of the lower house for many years. This being so, it is sometimes claimed that the upper house can bring to the scrutiny of proposed legislation experience and expertise which may be lacking in the lower house. This claim would seem to be particularly plausible when members of the upper house are appointed rather than elected and/or chosen from panels of those who have already distinguished themselves in public life (as is the case with, e.g., the Irish Seanad ). By the same token the claim has far less plausibility when membership of the upper house is determined in the same way as membership of the lower house, i.e., by direct election.
Freedom from short-term electoral concerns
Members of the upper house generally serve for longer terms than members of the lower house, in some legislatures may not be eligible for re-appointment or re-election when their term of service ends, and in others may be appointed for life – for more see Senate. Insofar as this is so, the upper house will be less susceptible than the lower house to influence by short-term electoral considerations: its members will be less likely to be deterred from supporting legislation they believe to be necessary by the knowledge that such support will make them unpopular with the electorate. Again, if membership of the upper house is by direct election, for a relatively short period of service, and re-election is permitted, this claim loses plausibility.
In some countries there are regions with particular interests or concerns which may be unlikely to receive adequate consideration in the lower house – perhaps these regions are sparsely populated and so have no more than minimal representation in the lower house. If membership of the upper house is based on different principles, these regional interests may be more likely to be accorded adequate consideration there. For example, in the United States the constituencies which form the basis for elections to the lower house (Congress) are roughly equal in terms of population size, which means that sparsely populated states have few congressional representatives - while California has 53 representatives, Texas 36, Florida 27 and New York 27, the states of Alaska, Delaware, Montana, North Dakota, South Dakota, Vermont and Wyoming have only one representative each. However, this state of affairs, which could lead to neglect of the interests of the minimally represented states, is mitigated in the upper house (Senate), where each state, irrespective of its population size, is represented by two senators.
Lengthier legislative process
Inevitably the legislative process is slower under a bicameral than under a unicameral system since, at the very least, proposed legislation must be scrutinised by two bodies rather than by one. The process may be even slower when the bicameral system requires proposed legislation not only to be scrutinised but to be approved by both houses so that amendments proposed by the second house are referred back to the first house for its approval. This can sometimes lead to proposed legislation being ‘shuttled’ between the two houses, as amendments approved by one house are referred back to the other house, which makes fresh amendments, which in turn require the approval of the second house, and so on. Where there is ‘perfect bicameralism’, i.e., complete legislative parity between the two houses so that proposed legislation must be approved in identical form by both houses, there can be deadlock if the two houses take very different views with regard to a piece of legislation and are unable to reach agreement. Though most bicameral legislatures have conventions for resolving protracted disagreement between the two houses, usually by allowing the will of the lower house to prevail, some do not – for example, the Italian parliament. (The Italian government’s recent proposal to make changes to the constitution which would have dispensed with the requirement for all legislation to be approved by the upper house (Senato) as well as by the lower house (Camera dei deputati) was rejected by the electorate in the referendum held on 4th December 2016.) Obviously, if there is not legislative parity between the two houses, and the upper house can only advise about legislation and/or delay its passage through the legislature, the problem of legislative deadlock between the two houses does not arise.
The great variety of bicameral legislatures makes it difficult to draw any general conclusions – save to say that, except when, e.g., a system produces legislative deadlock or slows the passage of legislation which needs approval as a matter of urgency, the advantage of a bicameral system in offering greater legislative scrutiny outweighs the disadvantage of its relative slowness: that the legislative outcome should be as good as possible matters more than the swiftness of the legislative process.
For discussion of other aspects of bicameralism see Bicameralism and democracy.