The concordance system is based on two principles
- an arithmetic rule, proportionality: the Federal Council should be representative of the political forces of the country, that is, its composition should be similar to that of the Federal Assembly.
- a political rule, consensus: the government must reach a compromise, even though it is composed of antagonistic parties.
One of the reasons explaining such a system (that also exists at the cantonal level, for partly similar and partly other reasons) is the "threat" of direct democracy, since a sizeable opposition could in principle "paralyse" the government by submitting too many referenda.
The fact that the members of the government must reach common decisions and stand by them is referred to as the principle of collegiality (German Kollegialitätsprinzip), (grounded in the Federal Constitution, art. 177 al.1). The members of the Federal Council are thus supposed to forgo party politics in the interest of a cooperative spirit among the members of the executive. They must defend the government's official positions, even if it goes against their personal views or those of their party.
- Since 1848 (when the new Federal Constitution made Switzerland a federation of States, and not a Confederation anymore, and thus introduced an executive organ at the federal level), the Swiss Federal Council has never been changed in its entirety, there have been only partial elections of some members. Thus, technically, Switzerland has always had the same government, stable and consensual, for as long as it has had one, in contrast to most Western democracies which see regular alternance between left and right major parties.
- The Concordance system started in 1891 with the election of Josef Zemp, a Christian Conservative, in a then entirely Free Democratic executive. The fact that this led to a reduced opposition from the outside of the government has since been referred to by Swiss political scientists as "The Zemp effect".
- From 1959 to 2003, the executive had the same party composition (2 Free Democratic Party, 2 Social Democratic, 2 Christian Democratic, and 1 Swiss People's Party.), based on the unwritten rule called the "magic formula". Since then, the composition changed to respect the proportionality rule after the rise of the Swiss People's Party.
- Pascal Sciarini, citing Raimund Germann, 2004, http://www.idheap.ch/idheap.nsf/go/1DC8268666521EA6C1256FDA00587659?OpenDocument&lng=it