The word pair rather… than… compares two hypothetical outcomes, often with the verb ‘would’. The two things being compared should be in the same grammatical form. Note especially that the word ‘to’ should not come after the word than, unless it also appeared after the word rather. Note also that the phrase rather than with no words in between (as in “They prefer to be right rather than wrong”) is not a conjunction.
Weather forecasters would rather be right than be wrong.
Weather forecasters would rather include rare scenarios than miss certain developments.