From a supply/demand perspective, there is no such thing as a shortage. At least not without further qualifications. Prices adjust so that the demand meets the supply. In theory that should always be possible. Concept of a shortage per se does not have a place in this theory. You can only speak about a shortage/oversupply at a certain price level but such a thing has no significant meaning because that price level is just an arbitrary number.
Thus to speak about a shortage you must add some other components to your model. Those other components will always be partially subjective (i.e., what you want to maximize?) and fairly complicated. (I believe.)
In any case, one could for example argue that there are not enough engineers to fill the roles "needed" in the economy at a sustainable price. (What is "needed", though?) But I am very sceptical about such a claim, considering the huge profits many US companies are making, even the software companies for that matter.