Stochastic Convenience Yield Implied from Commodity Futures and Interest Rates

We characterize a three‐factor model of commodity spot prices, convenience yields, and interest rates, which nests many existing specifications. The model allows convenience yields to depend on spot prices and interest rates. It also allows for time‐varying risk premia. Both may induce mean reversion in spot prices, albeit with very different economic implications. Empirical results show strong evidence for spot‐price level dependence in convenience yields for crude oil and copper, which implies mean reversion in prices under the risk‐neutral measure. Silver, gold, and copper exhibit time variation in risk premia that implies mean reversion of prices under the physical measure.     

Equilibrium Earnings Management,Incentive Contracts,and Accounting Standards*

In this paper, we model earnings management as a consequence of the interaction among self‐interested economic agents ‐ namely, the managers, the shareholders, and the regulators. In our model, a manager controls a stochastic production technology and makes periodic accounting reports about his or her performance; an owner chooses a compensation contract to induce desirable managerial inputs and reporting choices by the manager; and a regulatory body selects and enforces accounting standards to achieve certain social objectives. We show that various economic trade‐offs give rise to endogenous earnings management. Specifically, the owner may reduce agency costs by designing a compensation contract that tolerates some earnings management because such a contract allocates the compensation risk more efficiently. The earnings‐management activity produces accounting reports that deviate from those prescribed by accounting standards. Given such reports, the valuation of the firm may be nonlinear and s‐shaped, thereby recognizing the manager's reporting incentives. We also explore policy implications, noting that (1) the regulator may find enforcing a zero‐tolerance policy ‐ no earnings management allowed ‐ economically undesirable; and (2) when selecting the optimal accounting standard, valuation concerns may conflict with stewardship concerns. We conclude that earnings management is better understood in a strategic context that involves various economic trade‐offs.     

TOURISM,DUTCH DISEASE AND WELFARE IN AN OPEN DYNAMIC ECONOMY*

This paper examines the effects of an expansion in tourism on capital accumulation, sectoral output and resident welfare in an open economy with an externality in the traded good sector. An expansion of tourism increases the relative price of the nontraded good, improves the tertiary terms of trade and hence yields a gain in revenue. However, this increase in the relative price of nontraded goods results in a lowering of the demand for capital used in the traded sector. The subsequent de‐industrialization in the traded good sector may lower resident welfare. This result is supported by numerical simulations.     

When Is Sticky Information More Information?

This paper uses sectoral data to study survey‐based balance indices designed to capture changes in the business cycle in real time. The empirical framework recognizes that when answering survey questions regarding their firm's output, respondents potentially rely on infrequently updated information. The analysis then suggests that their answers reflect notable information lags, on the order of 7^1/2 months on average. Moreover, information stickiness implies that noisy output fluctuations will be attenuated in survey answers and, consequently, helps explain why balance indices successfully track business cycles. Conversely, in an environment populated by fully informed identical firms, as in the standard RBC framework, for example, balance indices instead become degenerate. Finally, information regarding changes in aggregate output tends to be sectorally concentrated. The paper, therefore, illustrates how this feature of the data may be relevant for the construction of balance indices.     

INNOVATION CYCLES AND LEARNING AT THE PATENT OFFICE: DOES THE EARLY PATENT GET THE DELAY?*

We study the relationship between the length of patent review and the importance of inventions. We build a simple model of the U.S. patent review process. Among the model predictions are that, controlling for a patent's position in a new technology cycle, more important innovations would be approved more quickly. Also, the approval delay is likely to decrease as an industry moves from the early stages of an innovation cycle to later stages. These predictions are in line with the evidence we obtain from a data set on U.S. patents granted in the field of genetically modified crops from 1983 to 1999. We also show that failing to account for the innovation lifecycle – as previous studies have done – is likely to bias upwards the estimates of the relationship between delay and importance.     

深度卷积神经网络在SAR自动目标识别领域的应用综述

深度卷积神经网络（DCNN）可自动学习目标层次化特征,在合成孔径雷达（SAR）自动目标识别（SAR-ATR）领域具有广泛应用前景。首先,介绍了DCNN的基本原理以及DCNN在光学图像上的应用与发展;然后,介绍了SAR-ATR的基本概念,综述了DCNN在SAR图像语义特征提取、片段级SAR图像分类、基于数据增强技术的SAR自动目标识别、异质图像变化检测等领域中的前沿应用研究及代表性网络架构;最后,总结并讨论了DCNN在SAR-ATR应用中存在的参数设置经验化、算法泛化能力较弱等不足,并对未来研究方向进行了展望。     

Transparency in the Financial System: Rollover Risk and Crises

We present a theory of optimal transparency when banks are exposed to rollover risk. Disclosing bank‐specific information enhances the stability of the financial system during crises, but has a destabilizing effect in normal economic times. Thus, the regulator optimally increases transparency during crises. Under this policy, however, information disclosure signals a deterioration of economic fundamentals, which gives the regulator ex post incentives to withhold information. This commitment problem precludes a disclosure policy that provides ex ante optimal insurance against aggregate shocks, and can result in excess opacity that increases the likelihood of a systemic crisis.     

The Complementarity Between Signal Informativeness and Monitoring

A firm that must decide whether to retain or terminate a manager can rely on several sources of information to assess managerial ability. When it relies on a performance signal and monitoring, we show that a more informative signal can surprisingly increase the value of monitoring. Then, signal precision and monitoring are complements. This happens if a more precise information system makes some signals more negative indicators of managerial ability that still do not trigger termination. When the turnover cost is high enough and the manager is more entrenched after a positive performance, an increase in signal precision increases expected monitoring. In firms with a high turnover cost, a less informative signal is compounded by worse monitoring after a disappointing performance. This “bad corporate governance trap” makes it hard for these firms to eventually improve performance.     

PESSIMISM OR OPTIMISM: A JUSTIFICATION TO VOLUNTARY CONTRIBUTIONS TOWARD ENVIRONMENTAL QUALITY*

This article analyses the determinants of voluntary contribution to environmental quality by introducing the perception of environmental risk. We consider individuals who are aware both of the impact of their voluntary contributions and of the quality of the current environment on the future quality of environment. Their preferences are represented by the RDU model. We distinguish three kinds of effect: environmental quality, wealth and risk perception. The first effects are not always sufficient to explain agents' implication in the improvement of environmental quality.