What is the best way to model economic externalities in pricing IT Services?

Lets look at some of the economic externalities/factors that impact a long-term pricing contract for IT Services (call it Outsourcing services):
1. Inflation
2. Cost of Living Adjustments
3. Foreign exchange volatility

Some of the above factors can lead to Operating margin erosions to tune of 10-15% if they are not built and recovered.

There are two ways in whic we can recover these costs
1. Engagement level: One by directly including it in every deal as part of the contract
2. Organization level: by currency hedging, managing cola & inflation internally through managed attrition :-)..

I'm now curious now what is the Accounting regulations that will support on inhibit either of the above model. or are there really none...

I've been struggling to get clarity on this and not being an accountant is a definite minus...Can someone help me here!