Conformal prediction interval estimation and applications to day-ahead and intraday power markets

In this study, we investigated the application of the conformal prediction (CP) concept in the context of short-term electricity price forecasting. In particular, we determined the most important aspects related to the utility of CP, as well as explaining why this simple but highly effective idea has proved useful in other application areas and why its characteristics make it promising for short-term power applications. We compared the performance of CP with various state-of-the-art electricity price forecasting models, such as quantile regression averaging, in an empirical out-of-sample study of three short-term electricity time series. We combined CP with various underlying point forecast models to demonstrate its versatility and behavior under changing conditions. Our findings suggest that CP yields sharp and reliable prediction intervals in short-term power markets. We also inspected the effects of each of the model components to provide path-based guideline regarding how to find the best CP model for each market.     

The Idiosyncratic Risk-Return Relation: A Quantile Regression Approach Based on the Prospect Theory

Given some debate on the empirical idiosyncratic risk-return relation in the literature, we reexamine the relation using a quantile regression approach based on the prospect theory developed by Kahneman and Tversky [1979]. The quantile regression approach allows the coefficient on the independent variable (idiosyncratic risk) to vary across the distribution of the dependent variable (return). Our sample consists of stocks traded on the NYSE, AMEX, and NASDAQ during 1980–2010: 80,324 firm-year observations and 8,123 firms in total. The quantile regression results show that idiosyncratic risk is positively (negatively) related to returns at the high (low) quantiles of returns. The findings are consistent with the prospect theory that investors have a tendency to be less (more) willing to gamble with profits (losses). The results also demonstrate that the least-squares and least-sum optimization methods commonly used in prior research do not capture the relations between idiosyncratic risk and returns at the tail parts of the distribution of returns. Therefore, our empirical results provide new insights into the idiosyncratic risk-return relation in the literature.     

Does the constraint matter? A note on the asymptotic properties of nonparametric instrumental variable estimation under monotonicity shape constraint

I show that constrained monotone instrumental variable estimators are asymptotically equivalent to their unconstrained counterparts whenever the true regression function is in the interior of the constrained set. In a simulation study, a sieve-based constrained estimator is shown to outperform the unconstrained one even in cases where both are asymptotically equivalent.     

地方政府环保投资规模影响因素分析及思考

运用逐步回归模型方法,探究影响地方政府环保投资规模的主要因素。研究表明:逐步回归分析法建立的数据模型具有很好的拟合效果,拟合度R2达0.806;同时得出地方财政收入、垃圾处理率、地区人口、人均公共绿地面积是影响地方环保投资的主要因素,其中效应最显著的是地方财政收入。据此,通过对影响因素分析提出了促进地方政府环保投资的对策建议:建立合理的地方环保激励机制以及加大中央财力支持可以缓解地方政府投资压力;多元环保投资体制建设可以为地方政府环保投资不足提供新的解决路径。     

Gender diversity and firm performance: evidence from India and Singapore

ABSTRACT

This study investigates if gender diversity on boards is an effective driver of financial performance. For this purpose, this study choses two countries, one of which has the soft law approach (Singapore) while the other has mandatory requirements (India) on corporate boards gender diversity. By doing so, it examines if there is a comparability between the listed firms of the two countries. Our results suggest that the gender diversity has a positive and significant effect on the financial performance of the firms of both the countries. Although, the gender diversity of the two countries does not seem to affect the growth opportunities of both the countries. Further, our results indicate that the board characteristics affect the performance positively and significantly when the sample is divided into five quantiles for the firms in these two countries. These findings have implications to the managerial decision making and relevance to stewardship theory and resource dependency theory.     

百分位数回归及应用研究

在进行定量分析时,最小二乘法已经成为一种可信赖的工具。但是运用最小二乘法的条件比较高,在实际问题中,完全满足条件的情况并不多见,那么在应用时就难以得到无偏的、有效的参数估计量。针对上述问题,以OILPLUS公司取暖用燃油消耗的分布为主要研究对象,在进行参数估计时,应用百分位数回归方法,既可以看到采用百分位数回归方法与采用最小二乘法得到的模型显著不同,又可以得到比最小二乘法更为丰富的信息。     

中国城镇居民消费的理性检验及实证研究

通过对1990-2003年中国城镇居民消费数据进行检验,否定了在此样本区间内消费主体的理性预期消费假设;并利用样本数据建立了满足统计检验要求的且与实际拟合较好的消费模型,得出结论:消费习惯和可支配收入的变动是影响城镇居民消费的最主要因素。     

Does a college education cause better health and health behaviours?

In this article, we exploit the recent higher education expansion in China to apply a regression discontinuity method to identify the causal effects of higher education on health and health behaviours. We do not find causal effect of a college education on better smoking and drinking behaviours. For our selected measures of health, we do not find causal effect of a college education on better self-assessed health, less chance of having illness in the past 3 months and keeping normal body weight; however, we find that a college education could significantly reduce the probability of having hypertension.     

Relative Age,Class Assignment,and Academic Performance: Evidence from Brazilian Primary Schools

Students in Brazil are typically assigned to classes based on the age ranking in their cohort. I exploit this rule to estimate how fifth‐grade students’ achievement in mathematics is affected when they are in classes with older peers. I find that being assigned to the older class leads to a drop in maths scores of about 0.4 of a standard deviation for students at the cut‐off. I provide evidence that heterogeneity in age is an important factor behind this effect. Information on teaching practices and student behaviour sheds light on how class heterogeneity harms learning.     

Inflation-unemployment tradeoff and regional labor market data

We estimate a linear and a piecewise linear Phillips curve model with regional labor market data for West German and Neue L?nder. Employing regional observations allows us to country difference the data. This eliminates, under the assumption of homogeneous L?nder, supply shocks and changes in the formation of expectations as possible identification failures. With seemingly unrelated regressions we find a flat Phillips curve in the Neue L?nder. For the West German L?nder a piecewise linear model with a higher inflation-unemployment tradeoff for the regime of low unemployment rates fits the data very well. The results hold true if we control for endogeneity of the unemployment rate. With a kinked but upward sloping aggregate supply curve there seems to be room for stabilization policies, at least in the range of aggregate demand shifts that our data covers. First version received: December 2000/Final version accepted: Jan. 2002 RID="*" ID="*"  An earlier version of this paper was written while the second author was at Universidad Carlos III in Madrid. He thanks Juan Dolado and is grateful for financial support by the TMR Program on New Approaches for the Study of Economic Fluctuations. He would also like to thank Bertrand Koebel for his critique on that earlier version. Both authors are grateful to an editor and three anonymous referees for very helpful comments. Moreover, we wish to thank participants of the seminar on Quantitative Wirtschaftsforschung by Jürgen Wolters and Peter Kuhbier, Freie Universit?t Berlin. Finally we profited from discussions with participants at the conferences of the European Economic Association in Lausanne and the Verein für Socialpolitik in Magdeburg where the paper was presented. Of course, all errors are to our sole responsibility.