Romer goes on to write:

Persistent disagreement is a sign that some of the participants in a discussion are not committed to the norms of science.

He should reread Kuhn. Kuhn says that the cause of persistent disagreement is usually the lack of a relevant and workable scientific paradigm which can identify important problems, resolve disputes, and thereby mandate researchers to come to consensus. Romer's use of the phrase "the norms of science" indicates that he believes in a singular, universal, monolithic set of principles which is valid for all types of scientific inquiry. But economists obviously cannot use the same principles as physicists, simply because they cannot run experiments. What Romer is really complaining about is that there is no good paradigm for economics, but that's not anyone's fault - the discovery and articulation of a paradigm is as difficult as doing the science that the paradigm supports. A more valid criticism of the field would be "We are trying to do science without a strong enough paradigm, and the weakness of the paradigm is preventing us from resolving our disagreements definitively. Instead of trying to do more research along the same old lines, we should go back to the philosophical foundations and re-examine what it means to do economics."