4.5 The liability criteria
The main principle that emerges through case law is that a liability for breach of established expectations depends on a relatively broad evaluation and balancing of, on the one hand, the basis and strength of the disappointed expectation, and on the other hand, the reason why the government failed to act in accordance with it. These criteria can be seen in connection with the more general requirements elucidated above, that government should act with due care towards private interests, which includes a general requirement of proportionality in public decision making.
In relation to the first criterion, it seems to be particularly relevant whether the expectation is induced by the relevant government authority through a clear and distinct representation, or promise meant to be relied on by specific individuals (cf. especially Rt. 1990 p. 1235), but this does not rule out that the possibility that other types of expectations which have a less distinctive basis may also be legitimate. It is, for instance, conceivable that this may include expectations as to a minimum measure of stability and predictability of future tariff policy, based on an existing regulatory framework or tariff structure.
In relation to the second criterion, assuming a certain expectation has been reasonably relied on in the first place, it will be of particular relevance whether the relevant government authority had both a good reason for disappointing the expectation, and was also to blame for creating it in the first place, although the latter is not necessarily a requirement. This can be seen both under the heading of a principle of proportionality and a duty of care. A possible line of reasoning would be that the government acts disproportionality or without due care if it does not take into account reasonable expectations relied on by a private party, which the government, through its acts or omissions, has contributed to creating.
It is also clear that the two criteria must be seen in tandem. If the government has made a strong and unambiguous promise, which is clearly meant to be relied on, towards an individual legal person, there must presumably be quite strong and overriding public reasons for disappointing the expectation, in order to escape liability. If, on the other hand, there are no distinct commitments or representations by the government, but instead merely expectations about a certain regulatory stability and continuity, it does not necessarily rule out liability if the government acts arbitrarily, outside the ordinary scope of actions, and disregards private interests without good cause. But this assumes a more lenient assessment requiring something equivalent to manifest unreasonableness and disproportionality, since the reasonable expectation in the first place is that the government has a general power to enact regulatory changes.