The majority of the criticisms of Proportional Representation (PR) are based around two broad themes:
- the tendency of PR systems to give rise to coalition governments with their attendant disadvantages; and
- the failure of some PR systems to provide a strong geographical linkage between an MP and the MP's electorate
The most cited arguments against using PR are that it leads to:
- Coalition governments, which in turn lead to legislative gridlock and the subsequent inability to carry out coherent policies at a time of most pressing need. There are particularly high risks during an immediate post-transition period, when new governments have huge expectations resting upon their shoulders. Quick and coherent decision-making can be impeded by coalition cabinets and governments of national unity which are split by factions.
- A destabilising fragmentation of the party system. PR reflects and facilitates a fragmentation of the party system. It is possible that such polarized pluralism can allow tiny minority parties to hold larger parties to ransom in coalition negotiations. In this respect, the inclusiveness of PR is cited as a drawback of the system. In Israel, for example, extremist religious parties are often crucial to government formation, while Italy has endured fifty years of unstable shifting coalition governments (see Electoral Reform in Israel).
- A platform for extremist parties. In a related argument, PR systems are often criticized for giving a parliamentary stage to extremist parties of the left or the right. It has been argued that the collapse of Weimar Germany was in part due to the way in which the PR electoral system gave a toe-hold to extremist groups.
- Governing coalitions which have insufficient common ground, in terms of either their policies or their supporter base. These 'coalitions of convenience' are sometimes contrasted with stronger 'coalitions of commitment' produced by other systems (e.g. the Alternative Vote), in which parties tend to be reciprocally dependent on the votes of supporters of other parties for their election.
- The inability to throw a party out of power. Under a PR system, it may be very difficult to remove a reasonably-sized party from power. When governments are usually coalitions, it is true that some political parties are ever-present in government, despite weak electoral performances from time to time. In the Netherlands, the Christian Democratic Appeal (CDA) remained the leading partner in government for seventeen years despite a declining vote share (see The Netherlands).
- A weakening of the link between MPs and their constituents. When simple List PR is used, and seats are allocated in one huge national constituency as in Namibia (see Namibia - National List PR in Southern Africa) or Israel (see Electoral Reform in Israel), the system is often criticized for destroying the link between voters and their member of parliament. Voters have no ability to determine the identity of the persons who will represent them, and no identifiable representative for their town, district, or village; nor do they have the ability to easily reject an individual if they feel they has behaved poorly in office. This factor has been particularly criticized in relation to some rural-based developing countries, where voters' identification with their region of residence is sometimes considerably stronger than their identification with any political party.
On a related point, national closed-list PR is criticized for leaving too much power entrenched within party headquarters and wielded by senior party leadership. A candidate's position on the party list, and therefore likelihood of success, is dependent on currying favour with party bosses, whose relationship with the electorate is of secondary importance.
Furthermore, the use of a PR system presumes some kind of recognized party structure, since voters are expected to vote for parties rather than individuals or groups of individuals. This makes List PR particularly difficult to implement, and probably less meaningful, in those societies which do not have parties, or have very embryonic and loose party structures (see Jordan - Electoral System Design in the Arab World).
Lastly, PR systems often have a barrier to surmount because they are still unfamiliar systems to many countries with English or French colonial histories, and because some variants are seen as being too complex for voters to understand or for the electoral administration to implement.
