Knowledge that Transforms

Recent empirical work on financial crises documents that crises tend to occur when macroeconomic fundamentals are weak; but even after conditioning on an exhaustive list of fundamentals, a sizable random component to crises and associated capital flows remains. We develop a model of herd behavior consistent with these observations. Informational frictions together with standard debt default problems lead to volatile capital flows resembling hot money and financial crises. We show that repaying debt during difficult times identifies a government as financially resilient, enhances its reputation, and stabilizes capital flows. Bailing out governments deprives resilient countries of the opportunity to differentiate themselves from the nonresilient.

In the United States, more than two‐thirds of decedents with multichild families divide their estates exactly equally among their children. In contrast, gifts given before death are usually unequal. These findings challenge the validity of existing theories regarding the determination of intergenerational transfers. In this paper, we develop a theory that accounts for this puzzle based on the notion that the division of bequests provides a signal about a parent’s altruistic preferences. The theory can also explain the norm of unigeniture, which prevails in other societies.

Gan and Vernon’s comment does not resolve the puzzle that we orig-inally posed. Their description of the puzzle is unclear, so we start by restating it. The essence of the matter is this. Imagine two households, one of which is larger than the other, for example, containing the same age and sex composition of people, but with twice as many of everyone. Imagine too that both households have the same level of per capita total house-hold expenditure so that, in the example, the household with twice as many people spends twice as much in total. If there are economies of scale, the second household is better off. While it is possible for it to maintain exactly the same expenditure pattern as the smaller household, with everyone having the same of everything, it can also rearrange its purchases to take advantage of the differential economies of scale in different goods. Because food is a normal good, we would expect the larger household to spend more per capita on food. This is especially so in poor countries, where there are few substitutes for food, so that there is limited opportunity for substituting away from food toward goods with greater economies of scale. The evidence contradicts this prediction. We looked at household survey data from the United States,

This paper describes the equilibrium of a discrete‐time exchange economy in which consumers with arbitrary subjective discount factors and homothetic period utility functions follow linear Markov consumption and portfolio strategies. Explicit expressions are given for state prices and consumption‐wealth ratios. We provide an analytically convenient continuous‐time approximation and show how subjective rates of time preference affect risk‐free rates but not instantaneous risk‐return trade‐offs. Hyperbolic discount factors can be a source of return volatility, but they cannot be used to address asset pricing puzzles related to high‐frequency Sharpe ratios.

Health care report cards–public disclosure of patient health outcomes at the level of the individual physician and/or hospital–may address important informational asymmetries in markets for health care, but they may also give doctors and hospitals incentives to decline to treat more difficult, severely ill patients. Whether report cards are good for patients and for society depends on whether their Þnancial and health beneÞts outweigh their costs in terms of the quantity, quality, and appropriateness of medical treatment that they induce. Using national data on Medicare patients at risk for cardiac surgery, we Þnd that cardiac surgery report cards in New York and Pennsylvania led both to selection behavior by providers and to improved matching of patients with hospitals. On net, this led to higher levels of resource use and to worse health outcomes, particularly for sicker patients. We conclude that, at least in the short run, these report cards decreased patient and social welfare. 1

A central statement of the theory of natural trading partners is that preferential trading with regional trading partners is less likely to be trade diverting and therefore geographically proximate partners are to be considered “natural” partners for preferential arrangements. This paper examines this question empirically. The analytical framework involves a general equilibrium model of preferential trade and an econometric model with tight links to this theory. This framework is used to implement tests of the natural trading partners hypothesis using U.S. trade data for the years 1964–95: Welfare changes that would result from preferential tariff reductions by the United States against various trading partners are first estimated, and correlations with bilateral “distance” measures (with and without controls for income levels) are then examined. Since the argument for “natural” trading partners is based on the greater likelihood of geographically proximate countries to be more significant trading partners, correlations between the welfare change estimates and bilateral trade volume are examined as well. Both geographic proximity and trade volume are found to have no effect. Thus this paper is unable to find any support for the natural trading partners theory in U.S. data.

The striking growth in the trade share of output is one of the most important developments in the world economy since World War II. Two features of this growth present challenges to the standard trade models. First, the growth is generally thought to have been generated by falling tariff barriers worldwide. But tariff barriers have decreased by only about 11 percentage points since the early 1960s; the standard models cannot explain the growth of trade without assuming counterfactually large elasticities of substitution between goods. Second, tariff declines were much larger prior to the mid 1980s than after, and yet, trade growth was smaller in the earlier period than in the later period. The standard models have difficulty generating this nonlinear feature. This paper develops a two-country dynamic Ricardian trade model that offers a resolution of these two puzzles. The key idea embedded in this model is vertical specialization, which occurs when countries specialize only in particular stages of a good's production sequence. The model generates a nonlinear trade response to tariff reductions and can explain over 50 percent of the growth of trade. Finally, the model has important implications for the gains from trade.

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.

Motivated by the behavior of asset prices, trading volume, and price volatility during episodes of asset price bubbles, we present a continuous-time equilibrium model in which overconfidence generates disagreements among agents regarding asset fundamentals. With short-sale constraints, an asset buyer acquires an option to sell the asset to other agents when those agents have more optimistic beliefs. As in a paper by Harrison and Kreps, agents pay prices that exceed their own valuation of future dividends because they believe that in the future they will find a buyer willing to pay even more. This causes a significant bubble component in asset prices even when small differences of beliefs are sufficient to generate a trade. In equilibrium, bubbles are accompanied by large trading volume and high price volatility. Our analysis shows that while Tobin's tax can substantially reduce speculative trading when transaction costs are small, it has only a limited impact on the size of the bubble or on price volatility.

When consumers share similar preferences, additional consumers will bring forth products that confer positive "preference externalities" on others. However, if distinct groups of consumers have substantially different preferences, the groups bring forth products with more appeal to themselves and less appeal to others. We document that in their capacity as daily newspaper consumers, blacks and whites are more likely to buy daily newspapers in markets with larger black and white populations, respectively. Similar results hold for Hispanics and non-Hispanics, but not by education, income, or age. We provide evidence that product positioning underlies our results.