In case of lost baggage, based on what does the airlines calculate value of lost baggage (and reimburse)? The replies to this question suggest buying insurance, but if one doesn't want to do that is there a way one can declare the value of belongings in checked in baggage ?
Each airline is different, however, most of them will inform you of this policy on their specific website. (For Example, Delta's policy.)
Also, keep in mind that most airlines will state that they are not liable for:
-Cash, camera equipment, fragile items, jewelry, etc...
For example, I have lost luggage with AA before, and I had to wait at least a week to give them a chance to find it, and I then filed a lost luggage declaration form, and spoke to a person in their Customer Service Dept. after my trip. It took some work, but I did get a fair value from them for my lost items (mainly clothing).
Bottom Line: Keep your valuables in your carry on, or on your person. Check each airline's Baggage Liability Rules. (Example.)