Tenure decisions and university rankings are just two examples where interfield comparison of academic output is needed. There are differences in publication performances among fields when the number of papers is used as the quantity measure and the Journal Impact Factor is used as the quality measure. For example, it is well known that the economics departments publish less than the chemistry departments and their journals have less impact factors. But there is no consensus on the magnitude of the difference and the methodology for the adjustment. Every decision maker makes his own adjustment and uses a different formula. In this paper, we quantify the publication performance differences among nine academic fields by using data from 1417 departments in the United States. We use two quality measures. First we weigh the publications by the impact factor of the journals. Second, we only consider the publications in the journals that are in the top quartile of the subject categories. We see that there are vast interfield differences in terms of the number of publications. Moreover, we find that the interfield differences are augmented when we consider the quality of the publications. Lastly, we rank the departments according to the quality of their graduate programs. We see that there are also huge differences among the departments with graduate programs of comparable rank.