Multiple entities in a document generally exhibit complex inter-sentence relations, and cannot be well handled by existing relation extraction (RE) methods that typically focus on extracting intra-sentence relations for single entity pairs. In order to accelerate the research on document-level RE, we introduce DocRED, a new dataset constructed from Wikipedia and Wikidata with three features: (1) DocRED annotates both named entities and relations, and is the largest humanannotated dataset for document-level RE from plain text; (2) DocRED requires reading multiple sentences in a document to extract entities and infer their relations by synthesizing all information of the document; (3) along with the human-annotated data, we also offer large-scale distantly supervised data, which enables DocRED to be adopted for both supervised and weakly supervised scenarios. In order to verify the challenges of documentlevel RE, we implement recent state-of-the-art methods for RE and conduct a thorough evaluation of these methods on DocRED. Empirical results show that DocRED is challenging for existing RE methods, which indicates that document-level RE remains an open problem and requires further efforts. Based on the detailed analysis on the experiments, we discuss multiple promising directions for future research. We make DocRED and the code for our baselines publicly available at https: //github.com/thunlp/DocRED. * indicates equal contribution

Why do governments bailout banking systems in distress? We argue that the government can efficiently provide liquidity. We present a general equilibrium model in which not all assets can be used to purchase all other assets at every date. At some dates agents want to sell projects or securities. The only buyers are agents who have previously opportunistically invested in otherwise dominated assets because only these ("liquid") assets can be used to purchase the projects or securities. The market price of the projects or securities sold depends on the supply of liquidity, which is determined in general equilibrium. The supply of liquidity is not perfectly elastic, so asset prices can deviate from "efficient market" prices, that is, the conditional expectation of the asset payoff. While private liquidity provision is socially beneficial since it allows valuable reallocations, it is also socially costly since liquidity suppliers could have made more efficient investments ex ante. As a result, there is a potential role for the government to supply liquidity by issuing government securities, backed by tax revenue. Government bailouts of banking systems are an example of such public liquidity provision.

Costly information acquisition makes it rational for investors to obtain important economic news with only limited frequency or limited accuracy. We show that this rational inattention to important news may make investors over- or underinvest. In addition, the optimal trading strategy is "myopic" with respect to future news frequency and accuracy. We find that the optimal news frequency is nonmonotonic in news accuracy and investment horizon. Furthermore, when both news frequency and news accuracy are endogenized, an investor with a higher risk aversion or a longer investment horizon chooses less frequent but more accurate periodic news updates. Copyright 2007 by The American Finance Association.

Partial ablation of the superior colliculus (SC) at birth in hamsters compresses the retinocollicular map, increasing the amount of visual field represented at each SC location. Receptive field sizes of single SC neurons are maintained, however, preserving receptive field properties in the prelesion condition. The mechanism that allows single SC neurons to restrict the number of convergent retinal inputs and thus compensate for induced brain damage is unknown. In this study, we examined the role of N-methyl-D-aspartate (NMDA) receptors in controlling retinocollicular convergence. We found that chronic 2-amino-5-phosphonovaleric acid (APV) blockade of NMDA receptors from birth in normal hamsters resulted in enlarged single-unit receptive fields in SC neurons from normal maps and further enlargement in lesioned animals with compressed maps. The effect was linearly related to lesion size. These results suggest that NMDA receptors are necessary to control afferent/target convergence in the normal SC and to compensate for excess retinal afferents in lesioned animals. Despite the alteration in receptive field size in the APV-treated animals, a complete visual map was present in both normal and lesioned hamsters. Visual responsiveness in the treated SC was normal; thus the loss of compensatory plasticity was not due to reduced visual responsiveness. Our results argue that NMDA receptors are essential for map refinement, construction of receptive fields, and compensation for damage but not overall map compression. The results are consistent with a role for the NMDA receptor as a coincidence detector with a threshold, providing visual neurons with the ability to calculate the amount of visual space represented by competing retinal inputs through the absolute amount of coincidence in their firing patterns. This mechanism of population matching is likely to be of general importance during nervous system development.

We develop a new theory of money and banking based on the old story in which goldsmiths start accepting deposits for safe keeping, then their liabilities begin circulating as media of exchange, then they begin making loans. We first discuss the history. We then present a model where agents can open bank accounts and write checks. The equilibrium means of payment may be cash, checks, or both. Sometimes multiple equilibria exist. Introducing banks increases the set of parameters for which money is valued-thus, money and banking are complements. We also derive a microfounded version of the usual money multiplier.The theory of banking relates primarily to the operation of commercial banking. More especially it is chiefly concerned with the activities of banks as holders of deposit accounts against which checks are drawn for the payment of goods and services. In Anglo-Saxon countries, and in other countries where economic life is highly developed, these checks constitute the major part of circulating medium. Encyclopedia Britannica (1954, vol. 3, p. 49).