Editorially, shift rates have gone up very little over the past decades. However, the cost of equipment has gone up astronomically and the job is no where as well paid as it used to be. Our workload has also gone up as we now do all the post processing as well.
In the days of film you could have a descent professional camera system for around £10,000, now days you're looking at more like £30,000. To top this, you also need to change cameras a lot more often as digital is changing and getting better at a very speedy rate. Lets not even talk about the computing technology making leaps and bounds.
Where we do have some control on the rates of pay is in the PR sector of the market. However, we choose to shoot ourselves in the foot. My rates haven't changed in years, and I stick to them no matter what the client says. Everyone tries it on; the client doesn't have enough money, the job's a quick one, its a hospital, its a charity etc. One thing you can be sure of is that the PR companies charge full wack, but they will always try and get the photographer for cheap so they can have a larger profit margin; why not? Its a business and they have to make money - but so do you.
The problem we all face is that less established and less experienced photographers are under charging massively for this type of work. PR rates have always been three to four times that of editorial work. However the thought process seems now days to be "well, some money is better than none" or "its better than doing an eight hour shift"! Painfully, its not just the less established photographers who have this philosophy; alas a few established names are also doing this.
In the short term this does mean more income. The thought being to make money. One of the excuses being "well the economy's not that strong". Be warned though; once you drop your rates and give discounts and do things like editing or wiring for free, you will never be able to get back to your normal charges when things get better. Its a one way street; there's no going back.
My advice and my way is to stick to my rates and not budge. For very regular clients I'll do DVDs for free, or drop a wiring charge as a token of appreciation for doing long term business. I know that once I give in to a cheaper rate, this rate will then be always expected regardless of who the end client is or how well the economy is doing.