While these figures are for the US, the UK situation is broadly similar. The loss of manufacturing jobs is not a result of trade or offshoring, rather of rising labour productivity.
When is a benefit of the Olympics not a benefit? When the Olympians take over your local sports hall or gym, of course.
Using statistics to work out whether MPs might be playing games with their expenses budgets. Of course, if they simply released the raw information these studies would not be necessary.