The idea that the happiness of an individual depends upon the consumption of others is widely viewed as an important feature of our shared social existence. Recent research in finance has used this idea, through consumption externalities, to explore asset-pricing anomalies. Consumption externalities potentially break the link between Pareto optimality and competitive equilibria and open the door for beneficial government intervention (e.g., Lars Ljungqvist and Harald Uhlig, 2000). In this paper, we delineate two effects that a consumption externality may have. An increase in aggregate consumption may: (a) raise the marginal utility of individual consumption relative to leisure, and/or (b) lower an individual’s utility level. We refer to (a) as “keeping up with the Joneses” (henceforth, KUJ), following Jordi Gali (1994), and we refer to (b) as jealousy. Jealousy is a distinct concept from KUJ. Under KUJ, an individual derives greater utility from additional own consumption relative to leisure when others consume more. At the same time, higher per capita consumption holding fixed individual consumption can trigger either jealousy, so that individual utility falls, or admiration, so that individual utility rises. In Section I of this paper, we show that jealousy implies that the laissez-faire equilibrium consumption level is greater than the optimal level. Whether preferences exhibit KUJ is not necessary for this main result. Intuitively, in the presence of jealousy, consumption is similar to pollution. Overpollution exists because individuals do not take into account the cost of polluting on others, not because an increase in economywide pollution makes the return to individual polluting higher. Similarly, overconsumption exists because individuals do not take into account the negative effect of own consumption on jealous others. Things go in the opposite direction when individuals are admiring. In Section II, we consider a functional form that encompasses several existing models. We show that jealousy determines the optimal tax to correct overconsumption and that KUJ is mainly important for asset pricing.

This paper presents a spatial econometric method for characterizing productivity comovement across sectors of the U.S. economy. Input‐output relations provide an economic distance measure that is used to characterize interactions between sectors, as well as conduct estimation and inference. We construct two different economic distance measures. One metric implies that two sectors are close to one another if they use inputs of other industrial sectors in nearly the same proportion, and the other metric implies that sectors are close if their outputs are used by the same sectors. Our model holds that covariance in productivity growth across sectors is a function of economic distance. We find that (1) positive cross‐sector covariance of productivity growth generates a substantial fraction of the variance in aggregate productivity, (2) cross‐sector productivity covariance tends to be greatest between sectors with similar input relations, and (3) there are constant to modest increasing returns to scale. We test and reject the hypothesis that these correlations are due to a common shock.