The phrase "theoretically should" is grammatically correct and can be used in written English.
It is usually used to describe a hypothetical or ideal situation, where something is expected to happen according to theory or principles, but may not always happen in reality. Example: Theoretically, this new technology should greatly improve efficiency, but in practice, there may be unforeseen challenges.
Mr Blinder wanted to know why prices are less flexible than they theoretically should be.
Thrust reversers are designed to help an aeroplane brake and theoretically should be impossible to deploy in midair.
"There are several billion dollars in P.S.A.'s every year; those theoretically should go back to the consumer," he said.
Every desk starts out pin neat; the clutter arrives with the user, and, at least theoretically, should depart with him.
These extra classes, theoretically, should help pull disadvantaged children out of the cycle of under-achievement to which they are currently consigned.
Observation status, which theoretically should last no more than a day or two, has been on the rise for longer stays.
"During the week they are giving support to politicians and union leaders as laborers and bodyguards by the very people that theoretically should be stopping them".
Lest we forget, Portugal has had two days' extra rest before this game and theoretically should be fresher, if the game goes into overtime.
Based on Friday's closing price in Paris for Vivendi of 86.5 euros a share, or $79.84, the 0.8-to-1 ratio means that Seagram theoretically should be trading at $63.87.
After ticketing and security processing, the average amount of free time a passenger has before a flight is 85 minutes, which theoretically should suggest lots of time for leisurely shopping or dining.
Jim Easton, one of the three American members of the International Olympic Committee, said yesterday that the awarding of the 2010 Winter Olympics to Vancouver, British Columbia, theoretically should not hurt New York's bid for the 2012 Olympics.
