Suppose economists develop an economic model and find that "it works great in theory, but it fails in practice." which of the following should the economists do next?
a. they should retest the current model, as there may have been an error in the testing methods the first time.
b. they should revise the model in light of its failure to explain or predict real world events.
c. they should leave the model as is. a model does not need to explain or predict real world events.
d. none of the above.