Forecasting the Covid-19 recession and recovery: Lessons from the financial crisis

We consider simple methods to improve the growth nowcasts and forecasts obtained by mixed-frequency MIDAS and UMIDAS models with a variety of indicators during the Covid-19 crisis and recovery period, such as combining forecasts across various specifications for the same model and/or across different models, extending the model specification by adding MA terms, enhancing the estimation method by taking a similarity approach, and adjusting the forecasts to put them back on track using a specific form of intercept correction. Among these methods, adjusting the original nowcasts and forecasts by an amount similar to the nowcast and forecast errors made during the financial crisis and subsequent recovery seems to produce the best results for the US, notwithstanding the different source and characteristics of the financial crisis. In particular, the adjusted growth nowcasts for 2020Q1 get closer to the actual value, and the adjusted forecasts based on alternative indicators become much more similar, all unfortunately indicating a much slower recovery than without adjustment, and very persistent negative effects on trend growth. Similar findings also emerge for forecasts by institutions, for survey forecasts, and for the other G7 countries.     

Correction to: Optimal and robust combination of forecasts via constrained optimization and shrinkage

We provide a correction to Proposition 1 in Optimal and robust combination of forecasts via constrained optimization and shrinkage, published in the International Journal of Forecasting 38(1):97-116 (2021). This correction has no impact on any other result (neither theoretical nor empirical) provided in the above paper.     

Combining prediction intervals in the M4 competition

The 2018 M4 Forecasting Competition was the first M Competition to elicit prediction intervals in addition to point estimates. We take a closer look at the twenty valid interval submissions by examining the calibration and accuracy of the prediction intervals and evaluating their performances over different time horizons. Overall, the submissions fail to estimate the uncertainty properly. Importantly, we investigate the benefits of interval combination using six recently-proposed heuristics that can be applied prior to learning about the realizations of the quantities. Our results suggest that interval aggregation offers improvements in terms of both calibration and accuracy. While averaging interval endpoints maintains its practical appeal as being simple to implement and performs quite well when data sets are large, the median and the interior trimmed average are found to be robust aggregators for the prediction interval submissions across all 100,000 time series.     

A hybrid information approach to predict corporate credit risk

This study proposes a hybrid information approach to predict corporate credit risk. In contrast to the previous literature that debates which credit risk model is the best, we pool information from a diverse set of structural and reduced‐form models to produce a model combination based on credit risk prediction. Compared with each single model, the pooled strategies yield consistently lower average risk prediction errors over time. We also find that while the reduced‐form models contribute more in the pooled strategies for speculative‐grade names and longer maturities, the structural models have higher weights for shorter maturities and investment grade names.     

Mixed-frequency approaches to nowcasting GDP: An application to Japan

In this paper, we discuss the approaches to nowcasting Japan’s GDP quarterly growth rates, comparing a variety of mixed frequency approaches including a bridge equation approach, Mixed-Data Sampling (MIDAS) and factor-augmented version of these approaches. In doing so, we examine the usefulness of a novel sparse principal component analysis (SPCA) approach in extracting factors from the dataset. We also discuss the usefulness of forecast combination, considering various ways to combine forecasts from models and surveys. Our findings are summarized as follows. First, some of the mixed frequency models discussed in this paper record out-of-sample performance superior to a naïve constant growth model. Second, albeit small, the SPCA approach of extracting factors improves predictive power compared with traditional principal component approach. Furthermore, we find that there is a gain from combining model forecasts and professional survey forecasts.     

马克思主义与中国实际相结合是制胜法宝*

中国共产党是在马克思主义指导下建立和发展起来的,马克思主义是中国共产党的行动指南。但是马克思主义并没有为中国革命道路和社会主义建设进程提供具体的路线图;中国的国情特殊且复杂,马克思和恩格斯著作没有也不可能给中国社会主义事业中的各种问题提供现成的答案。马克思主义必须联系中国实际、和中国具体实际相结合才有生命力,才能在实践中不断丰富和发展。中国共产党之所以由小到大、由弱到强,先后领导全国人民取得了新民主主义革命的胜利和社会主义革命与建设的胜利,开创了中国特色社会主义新时代,其制胜法宝就是坚持把马克思主义基本原理同中国具体实际相结合,同中华优秀传统文化相结合,不断推进马克思主义中国化时代化。     

矿泉水瓶再生设计研究

由于500ml左右矿泉水瓶瓶口具有统一的螺纹规格,其次,瓶体的容量也具有接近统一的标准,这就为矿泉水瓶再生设计的开发提供了必要的前提。市场上关于矿泉水瓶的再生设计多利用矿泉水瓶作为盛水的容器,而没有继续探讨其盛放小型垃圾(瓜子壳,纸屑,铅笔屑等)的功能。本文以绿色设计中延长产品生命周期的理念为原则,以联想法、模仿法及组合法等产品设计方法为指导,推出一款全新的使用矿泉水瓶衍生功能的产品,并着重介绍在本设计进行的过程中得出的新的设计方法:系统化条件下的功能衍生法。通过这款设计来说明现有产品衍生出新的功能的可行性,并总结一定的设计经验与设计方法,为以后进行相关设计奠定理论和方法基础。     

Electricity price forecasting: A review of the state-of-the-art with a look into the future

A variety of methods and ideas have been tried for electricity price forecasting (EPF) over the last 15 years, with varying degrees of success. This review article aims to explain the complexity of available solutions, their strengths and weaknesses, and the opportunities and threats that the forecasting tools offer or that may be encountered. The paper also looks ahead and speculates on the directions EPF will or should take in the next decade or so. In particular, it postulates the need for objective comparative EPF studies involving (i) the same datasets, (ii) the same robust error evaluation procedures, and (iii) statistical testing of the significance of one model’s outperformance of another.     

基于组合评价法的混流生产系统运行绩效评价

在目前集装箱制造行业转型升级的背景下，以某集装箱制造公司的特箱生产系统为例，构建混流生产系统运行绩效的评价指标体系，运用组合评价法对运行绩效进行评价。借鉴平衡计分卡的分析思路，对特箱生产系统的生产管理给出了相关的决策建议。此研究成果对其他制造型混流生产系统具有实际的指导意义。