(S (S (ADVP (NN Yesterday)) (COMMA ,) (S (BASENP (NNS economists)) (VP (VBD warned) (SBAR (IN that) (S (NP (BASENP (NN one)) (PP (IN of) (NP (NP (BASENP (DT the) (NNS impacts)) (PP (IN of) (BASENP (NNP Katrina)))) (PP (IN on) (BASENP (DT the) (NNP US) (NN economy)))))) (VP (MD would) (VP (VB be) (NP (NP (BASENP (DT a) (NN reduction)) (PP (IN in) (NP (BASENP (DT the) (NN number)) (PP (IN of) (BASENP (NNS jobs)))))) (PP (IN by) (NP (QP (ADVP (RB up) (TO to)) (NN 400,000)))))))))))) (PERIOD .))