Optimal dynamic scale and structure of a multi-pollution economy

We analyze the optimal dynamic scale and structure of a two-sector-economy, where each sector produces one consumption good and one specific pollutant. Both pollutants accumulate at different rates to stocks which damage the natural environment. This acts as a dynamic driving force for the economy. Our analysis shows that along the optimal time path (i) the time scale of economic dynamics is mainly determined by the lifetime of pollutants, their instantaneous harmfulness and the discount rate; (ii) economic scale and structure, as well as resulting welfare, may be non-monotonic, and (iii) environmental damage may exhibit an inverted U-shape form. These results raise important questions about the optimal design of environmental policies in a multi-pollution economy. We suggest a system of dynamic Pigouvian emission taxes, each of which should be levied specifically on one particular pollutant. We show that the optimal time path of each tax level is determined by the characteristics not only of that particular pollutant but also of all other pollutants.     

中国大中城市商业地产开发环境评价——基于时序全局主成分分析

2007年爆发的金融危机不但改变了全球经济格局,也增加了中国房地产市场的不确定性因素。随着住宅开发的竞争越来越激烈,其利润率呈现走低趋势。越来越多的房地产开发商从住宅地产转向商业地产领域,以期获得更加丰厚的回报。选取中国35个大中城市的42个变量共计近6000个数据,利用时序全局主成分分析法对后金融危机时期的这些城市商业地产开发环境进行了系统研究,建立了比较科学的评价指标体系。     

农村信贷配给实证分析

信贷配给是制约我国农村信贷市场建设的重要因素,也阻碍了农村金融环境优化、影响了农村经济的良性发展。通过引入制度因子,量化信贷配给,构建了信贷配给宏观计量模型,对我国农村信贷配给状况进行实证检验,结果证明,利率和制度因子是造成我国农村信贷配给的两大因子。应合理调控利率、推进深化改革、加大三农扶持力度,实现农村经济社会的和谐发展。     

Regulation of relationships between heterogeneous farmers and an aquifer accounting for lag effects

Many environmental problems are due to damage caused by pollutants that accumulate with a time lag following their emission. In this study, we focus on nitrates used in agriculture, which can pollute groundwater many years after their initial application. A dynamic optimal control problem with heterogeneous farmers is proposed. The usual structural parameters such as the discount rate, the natural clearing rate and the lagged time interval between the occurrence of soil‐level pollution and the impact on groundwater are taken into account. We also examine pollution as caused by a continuous set of farms characterised by their individual performance index and by their individual marginal contribution to the pollution. The issue is further investigated by taking account of change in the information context, successively related to perfect information and to asymmetric information. As a result, when the delay between the spreading of N‐fertilizer and the impact on the aquifer increases, that is, the longer the lag, the steady‐state pollution stock and the steady‐state shadow price of the stock both increase. Moreover, we show that the optimal regulation may require a decreasing amount of fertilizer over time, even in the case of initial underpollution.     

Markov-switching dynamic factor models in real time

We extend the Markov-switching dynamic factor model to account for some of the specificities of the day-to-day monitoring of economic developments from macroeconomic indicators, such as mixed sampling frequencies and ragged-edge data. First, we evaluate the theoretical gains of using data that are available promptly for computing probabilities of recession in real time. Second, we show how to estimate the model that deals with unbalanced panels of data and mixed frequencies, and examine the benefits of this extension through several Monte Carlo simulations. Finally, we assess its empirical reliability for the computation of real-time inferences of the US business cycle, and compare it with the alternative method of forecasting the probabilities of recession from balanced panels.     

Pricing of the time-change risks

We develop an equilibrium endowment economy with Epstein-Zin recursive utility and a Lévy time-change subordinator, which represents a clock that connects business and calendar time. Our setup provides a tractable equilibrium framework for pricing non-Gaussian jump-like risks induced by the time-change, with closed-form solutions for asset prices. Persistence of the time-change shocks leads to predictability of consumption and dividends and time-variation in asset prices and risk premia in calendar time. In numerical calibrations, we show that the risk compensation for Lévy risks accounts for about one-third of the overall equity premium.     

Riding the Ever-Rolling Stream: Time and the Ontology of Violent Conflict

In this paper, we examine the ways in which the passage of time is dealt with in econometric studies of violent conflict and civil war with empirical attention to the dynamics of ethnic conflict. We argue that the mainstream approach to econometric studies of civil war is based on a time-invariant ontology and that this is not an appropriate or adequate way of capturing the causal patterns of violent conflict. Based analysis of replication datasets using structural break analysis and rolling windows, we show how careful attention to the passage of time reveals important macro-historical changes in the coefficients on ethnic diversity in explaining conflict incidence. We conclude that econometric studies of civil war need to pay more careful attention to the limitations on the generalizations that they draw through attention to the passage of time and better iteration with qualitative and historical studies.     

Choice of Portfolios and Fee under Principal -Agent Framework with Uncertain Exit - Time

In the real world, an investor is usually not sure about when he or she will exit investment. She can only make estimation prior. With the growth of the scale of open - end funds which can be subscribed and redeemed at any time. Investors began to pay more attention on problems such as whether the fee is reasonable, the payment can encourage the agent or not. Others would consider if the portfolio that the agent chooses is the best one. This paper considers the principal - agent problem with uncertain exit - time under two cases： the action of the agent is observable and unobservable. We derive close - form expressions of the optimal portfolio and the best fee. Finally an empirical analysis is given based on the data of some open - end funds in China.     

A nonlinear long memory model, with an application to US unemployment

Two important empirical features of US unemployment are that shocks to the series seem rather persistent and that it seems to rise faster during recessions than that it falls during expansions. To jointly capture these features of long memory and nonlinearity, we put forward a new time series model and evaluate its empirical performance. We find that the model describes the data rather well and that it outperforms related competitive models on various measures of fit.     

Time series momentum and moving average trading rules

We compare and contrast time series momentum (TSMOM) and moving average (MA) trading rules so as to better understand the sources of their profitability. These rules are closely related; however, there are important differences. TSMOM signals occur at points that coincide with a MA direction change, whereas MA buy (sell) signals only require price to move above (below) a MA. Our empirical results show MA rules frequently give earlier signals leading to meaningful return gains. Both rules perform best outside of large stock series which may explain the puzzle of their popularity with investors, yet lack of supportive evidence in academic studies.