National Bureau of Economic Research

About: National Bureau of Economic Research is a nonprofit organization based out in Cambridge, Massachusetts, United States. It is known for research contribution in the topics: Monetary policy & Population. The organization has 2626 authors who have published 34177 publications receiving 2818124 citations. The organization is also known as: NBER & The National Bureau of Economic Research.

Separate Neural Systems Value Immediate and Delayed Monetary Rewards

Abstract: When humans are offered the choice between rewards available at different points in time, the relative values of the options are discounted according to their expected delays until delivery. Using functional magnetic resonance imaging, we examined the neural correlates of time discounting while subjects made a series of choices between monetary reward options that varied by delay to delivery. We demonstrate that two separate systems are involved in such decisions. Parts of the limbic system associated with the midbrain dopamine system, including paralimbic cortex, are preferentially activated by decisions involving immediately available rewards. In contrast, regions of the lateral prefrontal cortex and posterior parietal cortex are engaged uniformly by intertemporal choices irrespective of delay. Furthermore, the relative engagement of the two systems is directly associated with subjects' choices, with greater relative fronto-parietal activity when subjects choose longer term options.

Myopic loss aversion and the equity premium puzzle

Abstract: The equity premium puzzle refers to the empirical fact that stocks have outperformed bonds over the last century by a surprisingly large margin. We offer a new explanation based on two behavioral concepts. First, investors are assumed to be "loss averse," meaning that they are distinctly more sensitive to losses than to gains. Second, even long-term investors are assumed to evaluate their portfolios frequently. We dub this combination "myopic loss aversion." Using simulations, we find that the size of the equity premium is consistent with the previously estimated parameters of prospect theory if investors evaluate their portfolios annually. There is an enormous discrepancy between the returns on stocks and fixed income securities. Since 1926 the annual real return on stocks has been about 7 percent, while the real return on treasury bills has been less than 1 percent. As demonstrated by Mehra and Prescott [1985], the combination of a high equity premium, a low risk-free rate, and smooth consumption is difficult to explain with plausible levels of investor risk aversion. Mehra and Prescott estimate that investors would have to have coefficients of relative risk aversion in excess of 30 to explain the historical equity premium, whereas previous estimates and theoretical arguments suggest that the actual figure is close to 1.0. We are left with a pair of questions: why is the equity premium so large, or why is anyone willing to hold bonds? The answer we propose in this paper is based on two concepts from the psychology of decision-making. The first concept is loss aversion. Loss aversion refers to the tendency for individuals to be more sensitive to reductions in their levels of well-being than to increases. The concept plays a central role in Kahneman and Tversky's [1979] descriptive theory of decision-making under

The External Wealth of Nations Mark Ii: Revised and Extended Estimates of Foreign Assets and Liabilities, 1970-2004

Abstract: We construct estimates of external assets and liabilities for 145 countries for the period 1970-2004. We describe our estimation methods and present key features of the data at the country and the global level. We focus on trends in net and gross external positions, and the composition of international portfolios, distinguishing between foreign direct investment, portfolio equity investment, official reserves, and external debt. We document the increasing importance of equity financing and the improvement in the external position for emerging markets, and the differing pace of financial integration between advanced and developing economies. We also show the existence of a global discrepancy between estimated foreign assets and liabilities, and identify the asset categories that account for this discrepancy.

Increasing Returns and Economic Geography

Abstract: This paper develops a two-region, two-sector general equilibriun model of location. The location of agricultural production is fixed, but ionopolistcally competitive manufacturing finns choose their location to maximize profits. If transportation costs are high, returns to scale weak, and the share of spending on manufactured goods low, the incentive to produce close to the market leads to an equal division of manufacturing between the regions. With lower transport costs, stronger scale economies, or a higher manufacturing share, circular causation sets in: the more manufacturing is located in one region, the larger that region's share of demand, and this provides an incentive to locate still more manufacturing there. Thus when the parameters of the economy lie even slightly on one side of a critical "phase boundary", all manufacturing production ends up concentrated in only one region.