Knowledge that Transforms

The norming of the third edition of the Test of Understanding College Economics (TUCE III) has produced a valuable data set (Phillip Saunders, 1994). These data describe 93 introductory macro and 96 introductory microeconomics classes taught by 131 different instructors at 53 U.S. colleges and universities in 1989-1990. It is tempting to use this sample to investigate how class size influences learning. The nonexperimental nature of the data, however, raises the possibility of an endogeneity problem: department chairs may assign better teachers to larger classes, and those teachers, in turn, may attract even greater numbers of students. Teaching quality, therefore, may be higher in larger classes. Thus, the discovery from these data of any deleterious effect on learning from larger classes may be only a lower bound. The education literature, admirably surveyed by Wilbert J. McKeachie (1990), suggests that learning is not much affected by class size. One reason for this result may be that instructors do not adjust their teaching methods to class size. In this paper we use the TUCE III data to examine whether introductory economics instructors vary pedagogy with class size. I. The Role of Instructor Behavior

The effects of seat-belt regulations on automobile-related fatality and injury rates have been of great interest to economists and policy-makers over the past few years.' The effects of the laws have been evaluated by various statistical techniques using timeseries data for particular states and pooled time-series data for national models.2 The results of these studies provide some evidence that seat-belt laws (SBL) reduce injury and fatality rates. However, the effects of seat-belt laws vary across states and time periods as well as across the levels of injuries. This study assesses the effects of the Texas seat-belt law on injury rates using policereported accident data. The data are from the U.S. Department of Transportation State Traffic Accident Files and are compiled monthly for the period 1982-1987 for driver-involved accidents. Furthermore, the data comprise singleand multiple-vehicle accidents. Only accidents involving towed vehicles are used in the analysis so as to normalize for changes in accident-reporting thresholds over time.3 The analysis was conducted for several sets of injury classifications using the KABCO scale, which indicates the numbers of fatalities (K), severe injuries (A), moderate injuries (B), complaints of injuries (C), and no injuries (0).

A countertrade contract ties an export to an import. Usually, countertrade is criticized as a form of bilateralism and reciprocity and, thus, as an inefficient form of international exchange. In this paper, the authors argue that there are circumstances in which the tying of two technologically unrelated trade flows may be efficiency-enhancing. They show that countertrade can be an efficient institution in international trade that solves moral-hazard problems and restores creditworthiness of highly indebted countries. The authors test the implications of their model using a sample of 230 countertrade contracts. Copyright 1995 by American Economic Association.

Investigates the effecto of the North American Free Trade Agreement on agriculture in Mexico. Implications on policy design for the absence of efficient capital markets, on the welfare costs of reforming gradually, on incentive problems created by trade adjustement policies and on the redistribution aspects of policy reform.