Knowledge that Transforms

There is a growing consensus that emissions of greenhouse gases due to human activity will alter the earth’s climate, most notably by causing temperatures, precipitation levels, and weather variability to increase. The design of optimal climate change mitigation policies requires estimates of the health and other benefits of reductions in greenhouse gases; current evidence on the magnitude of the direct and indirect impacts, however, is considered insufficient for reliable conclusions (A. J. McMichael et al. 2003).

Shocks to the real price of oil may reflect oil supply shocks, shocks to the global demand for all industrial commodities, or demand shocks that are specific to the crude oil market. Each shock has different effects on the real price of oil and on US macroeconomic aggregates. Changes in the composition of shocks help explain why regressions of macroeconomic aggregates on oil prices tend to be unstable. Evidence that the recent surge in oil prices was driven primarily by global demand shocks helps explain why this shock so far has failed to cause a major recession in the United States.

This short paper argues that the view that monetary policy is ineffective during financial crises is not only wrong, but may promote policy inaction in the face of a severe contractionary shock. To the contrary, monetary policy is more potent during financial crises because aggressive monetary policy easing can make adverse feedback loops less likely. The fact that monetary policy is more potent than during normal times provides a rationale for a risk-management approach to counter the contractionary effects from financial crises, in which monetary policy is far less inertial than would otherwise be typical -not only by moving decisively through conventional or nonconventional means to reduce downside risks from the financial disruption, but also in being prepared to quickly take back some of that insurance in response to a recovery in financial markets or an upward shift in inflation risks.

What caused the financial crisis that is sweeping across the world? What keeps asset prices and lending depressed? What can be done to remedy matters? While it is too early to arrive at definite answers to these questions, it is certainly time to offer informed conjectures, and these are the focus of this paper.

This paper explores a general model of the evolution and adaption of hedonic utility. It is shown that optimal utility will be increasing strongly in regions where choices have to be made often and decision mistakes have a severe impact on fitness. Several applications are suggested. In the context of intertemporal preferences, the model offers an evolutionary explanation for the existence of conflicting short- and long-run interests that lead to dynamic inconsistency. Concerning attitudes toward risk, an evolutionary explanation is given for S-shaped value functions that adjust to the decision maker's environment.

Beginning with Wilfred J. Ethier (1979, 1982), an important current of research has emphasized gains to trade from the greater availability of intermediate inputs, as opposed to the greater availability of consumption goods emphasized by Paul R. Krugman (1979) and others. It has been standard in this literature to model input varieties as symmetric, differentiated horizontally but not vertically. In contrast, anecdotal accounts, especially from developing countries, often stress the importance of gaining access to high-quality inputs on the import market. In theoretical discussions, the need to distinguish between the number of inputs and the quality of those inputs can be avoided by treating different qualities of a good as distinct varieties (see, e.g., Paul Romer 1994) or by redefining units of measurement. But in empirical work, one inherits the product categories and units in the data, and typically one must specify whether the availability-of-inputs mechanism is expected to operate through an increase in the number of input categories or through an increase in the quality of inputs within categories. Because of data constraints—in particular because of a lack of information on input and output prices in standard plant-level datasets—it has been difficult to investigate the role of input-quality differences, and recent empirical work, notably by Christian Broda, Joshua Greenfield, and David Weinstein (2006) and Pinelopi K. Goldberg et al. (2008), has tended to focus more on changes in the number of input categories than on quality differences within those categories. In this short paper, we draw on rich product level information from the Colombian manufacturing census to present a new set of facts about importing plants and input prices. The dataset is unique in that it contains detailed, representative, consistently measured information on the unit values of all inputs and outputs of plants. For the 1982–1988 period, the dataset also contains unit values separately for domestic and imported purchases of each input. As we discuss in more detail below, we interpret the new facts as suggesting that Colombian plants purchase higher-quality inputs on the import market than on the domestic market, within narrow product categories. Our empirical work has been guided in part by a theoretical framework from a related paper, Kugler and Verhoogen (2008). In that paper, we hypothesize a complementarity between input quality and plant productivity in generating output quality, and extend the model of Marc J. Melitz (2003) to accommodate it. The model predicts that, in equilibrium, more-productive plants are larger, use higher-quality inputs, produce higher-quality outputs, and are more likely to enter the export market than less-productive plants in the same industry. Using the Colombian plant census, we show that the cross-sectional correlations between a number of observable variables—output prices, input prices, plant size, and export status—as well as differences in those correlations across sectors,—are consistent with our theoretical framework and difficult to reconcile with alternative models that impose symmetry of either inputs or outputs. The distinctive aspect of the current paper is the focus on the distinction between imported and domestic inputs.

We propose a distinction between active and passive waste as determinants of the cost of public services. Active waste entails utility for the public decision maker, whereas passive waste does not. We analyze purchases of standardized goods by Italian public bodies and exploit a policy experiment associated with a national procurement agency. We find that: (i) some public bodies pay systematically more than others for equivalent goods; (ii) differences are correlated with governance structure; (iii) the variation in prices is principally due to variation in passive rather than active waste; and (iv) passive waste accounts for 83 percent of total estimated waste.

Food choice decisions are not the same as intake volume decisions. The former determine what we eat (soup or salad); the latter determine how much we eat (half of the bowl or all of it). Large amounts of money, time, and intelligence have been invested in understanding the physiological mechanisms that influence food choice (James O. Hill, forthcoming). Much less has been invested in understanding how and why our environment influences food consumption volume. Yet environmental factors (such as package size, plate shape, lighting, variety, or the presence of others) affect our food consumption volume far more than we realize (Wansink 2006). Whereas people can acknowledge that environmental factors influence others, they wrongly believe they are unaffected. Perhaps they are influenced at a basic level of which they are not aware. A better understanding of these drivers of consumption volume will have immediate implications for research, policy, and personal interventions. There are three objectives of this paper: (1) explain why environmental factors may unknowingly influence food consumption; (2) identify resulting myths that may lead to is specified models or misguided policy recommendations; and (3) offer clear direction for future research, policy, and personal dietary efforts.

This paper reports the results of an experiment designed to assess the ability of an incumbent seller to profitably foreclose a market with exclusive contracts. We use the strategic environment described by Rasmusen, Ramseyer, and Wiley (1991) and Segal and Whinston (2000) where entry is unprofitable when sufficiently many downstream buyers sign exclusive contracts with the incumbent. When discrimination is impossible, the game resembles a stag-hunt (coordination) game in which the buyers' payoffs are endogenously chosen by the incumbent seller. Exclusion occurs when the buyers fail to coordinate on their preferred equilibrium. Two-way non-binding pre-play communication among the buyers lowers the power of exclusive contracts and induces more generous contract terms from the seller. When discrimination and communication are possible, the exclusion rate rises. Divide-and-conquer strategies are observed more frequently when buyers can communicate with each other. Exclusion rates are significantly higher when the buyers' payoffs are endogenously chosen rather than exogenously given. Finally, secret offers are shown to decrease the incumbent's power to profitably exclude.

I examine excise taxes levied on multiproduct retailers. Excise taxes reduce equilibrium output and decrease equilibrium product variety in the short run, but taxes can raise output per product in the long run and induce entry. Excise taxes are overshifted into prices in a wide range of cases, including under linear and concave demand conditions, and excise taxes shift less than one-for-one into prices only when demand is highly convex. Multiproduct transactions substantively alter the efficiency of ad valorem and specific forms of excise taxes and affect the comparison of relative tax performance over short-run and long-run time horizons.