There may be upside benefits from changes instituted by the state government or its agencies. These should be credited against any downside risk government agrees to take. This might be done either (or both) in relation to particular changes - making the relevant concept the net change, balancing downside and upside consequences - or by effectively maintaining a ledger, so that any credits arising from government action can be banked against any later adverse changes. Though attractive in theory, it is acknowledged that this may be difficult to implement in practice.
Where such sharing mechanisms are used in relation to change in law, detailed contractual provisions are required to enable identification of the consequences of the change. Quantifying the true cost of a change in law is particularly difficult when it indirectly impacts on the project or requires modification of the operating regime.
Where symmetrical risk allocation is to be pursued, it is important to consider any taxation or balance-sheet consequences from profit-sharing in risk upsides.