Which period of economic recession are you referring to?
Your teacher's version refers to recessions in general. "During" is as good as "in". The teacher's sentence makes sense as a stand alone sentence, while yours doesn't.
You could have written, "during this period of economic recession" or "during periods of economic recession" or "People needed ... during the recession" (if the particular recession has already been made clear.
Your teacher isn't wrong, but it depends on the intended meaning.
Student or Learner