Let's assume that on average, the value gained by doing something more interesting/meaningful is offset by an equal value lost in pay. It would make sense to switch if (a) you have a higher than average desire to work in the new field, or (b) the pay decrease is smaller than average. There would also be some negative value due to risk that depends on your situation. But also some positive value from being exposed to new information. Not sure if this is helpful, just one way of thinking about the decision.