Forecast combinations of computational intelligence and linear models for the NN5 time series forecasting competition

In this work we introduce the forecasting model with which we participated in the NN5 forecasting competition (the forecasting of 111 time series representing daily cash withdrawal amounts at ATM machines). The main idea of this model is to utilize the concept of forecast combination, which has proven to be an effective methodology in the forecasting literature. In the proposed system we attempted to follow a principled approach, and make use of some of the guidelines and concepts that are known in the forecasting literature to lead to superior performance. For example, we considered various previous comparison studies and time series competitions as guidance in determining which individual forecasting models to test (for possible inclusion in the forecast combination system). The final model ended up consisting of neural networks, Gaussian process regression, and linear models, combined by simple average. We also paid extra attention to the seasonality aspect, decomposing the seasonality into weekly (which is the strongest one), day of the month, and month of the year seasonality.     

The distributive and welfare effects of product and labour market deregulation

This paper studies the effects of product and labour market deregulation on wage inequality and welfare. By constructing an analytically tractable model in which the level of product market competition and the wages are endogenously distributed among sectors, I show that deregulation in goods market has mixed effects on inequality: the wage variance and the Gini index are lower, but the ratio of the highest over the lowest wage paid in the economy increases. Moreover, deregulation in labour markets raises the aggregate level of employment and the average real wage but reduces the welfare of trade unions in sectors with a low level of competition.     

采用数据辅助的大规模MIMO信道半盲迭代估计

由于大规模多输入多输出(Multiple-Input Multiple-Output,MIMO)信道衰落参数的维度较高,导致最优估计算法计算量大且需要的导频数较多而影响到频谱效率。为降低计算复杂度并减少导频开销,提出了两种基于期望最大化(Expectation Maximization,EM)估计的半盲迭代改进算法。利用少量正交导频序列估计出信道初值,通过用户与基站间信道的大尺度衰落系数把用户分簇,根据这些系数按比例地分配接收噪声,再利用数据的统计特性推导出信道衰落参数的均值和方差。仿真结果表明,当导频数远少于待估计参数的个数时,半盲估计算法的均方误差(Mean Square Error,MSE)优于导频估计的极大似然(Maximum likelihood,ML)算法。     

一种3.5 GHz频段双通道射频前端设计

随着5G商用网络的快速建设,国内5G网络测试设备存在大量空缺。为此,设计了一种适用于5G终端模拟器的3.5 GHz频段双通道射频前端。该射频前端结合了ADRV9009芯片,可同时支持双通道收发,具有器件数少、设计复杂度低的特点。实测结果表明,该射频前端性能稳定,接收灵敏度为-85 dBm,噪声系数小于2.6 dB,256QAM调制下发射信号的误差矢量幅度为1.43%,达到了5G终端模拟器的设计要求。     

The impact of news,oil prices,and global market developments on Russian financial markets1

This paper analyses the impact of news, oil prices, and international financial market developments on daily returns on Russian bond and stock markets. First, regarding returns, energy news affects returns, while news from the war in Chechnya is not significant. Market volatility does not appear to be sensitive to either type of news. Second, a significant effect of the growth in oil prices on Russian stock returns is detected. Third, the international influence on Russian financial markets depends upon the degree of financial liberalization. The higher the degree of financial liberalization, the stronger is the impact of US stock returns on Russian financial markets. In addition, banking reform and interest rate liberalization efforts seem to dictate the globalization of Russian stock markets, while it is the progress in liberalizing securities markets and non‐bank financial institutions that matters more for the globalization of Russian bond markets.     

Does fiscal policy influence monetary policy? The case of Spain, 1874-1935

The Spanish peseta never formally belonged to the gold club, neither the classical nor the exchange-rate gold standards. It has been traditionally argued that the reason was the predominance of deficits in the Spanish budget from 1874 to 1935. The financing needs of the Treasury led to money creation and, consequently, to sacrificing the gold commitment and a fixed exchange rate. Applying a stationary VAR (Vector AutoRegressive) model, this paper estimates the dynamic link between budget and money and tests whether Spanish fiscal policy actually influenced monetary policy. The results confirm the dominance of fiscal policy for the period and, therefore, provide empirical support to the idea that the problems of the Treasury were behind Spain’s renouncement of gold.     

Unions: Rent Creators or Extractors?*

This paper proposes a model of workplace‐specific unions that integrates two views of what unions do. One view holds that unions mainly engage in rent extraction. Another view holds that unions mainly engage in rent creation by providing agency services that increase workplace productivity. We demonstrate that the choice between the two activities is systematically related to the economic and regulatory environment in which the union operates. Product market competition encourages rent creation, while labor market deregulation encourages rent extraction. Moreover, we provide a rationale for why firms may want to subsidize unions.     

Do Investors Care about the Auditor's Economic Dependence on the Client?*

In this study, we investigate whether investor perceptions of the financial reporting credibility of Big 5 audits are related to the auditor's economic dependence on the client as measured by nonaudit as well as total (audit and nonaudit) fees paid to the incumbent auditor. We use the client‐specific ex ante cost of equity capital as a proxy for investor perceptions of financial reporting credibility and examine auditor fees both as a proportion of the revenues of the audit firm and as a proportion of the revenues of the audit firm's practice office through which the audit was conducted. Our findings suggest that both nonaudit and total fees are perceived negatively by investors' that is, the higher the fees paid to the auditor, the greater the implied threat to auditor independence, and the lower the financial reporting credibility of a Big 5 audit. Furthermore, our findings appear to be largely unrelated to corporate governance: investors do not perceive the auditor as compensating for weak governance. Separately, recent anecdotal evidence suggests that declining revenues from nonaudit services' as a result of recent regulatory restrictions” are being offset by substantial increases in audit fees. Other things being equal, rising audit fees imply higher profit margins for audit services, indicating that the audit function may no longer be a loss leader. Thus, to the extent that investors perceive total fees negatively, recent regulatory initiatives to limit nonaudit fees may not have adequately addressed the perceived, if not the actual, threat to auditor independence posed by fees.     

A new proposal for the reunification of the two Koreas: Economic issues

We present an alternative five-step plan which not only supplements the deficiencies of the current official plans for reunification, but also incorporates recent developments, such as, joint membership of North and South Korea of the United Nations (1991), and mutual agreements on reconciliation, nonaggression and economic exchange and cooperation (1992). The plan starts with a preliminary step for the normalization of relations between the two Koreas, and then subsequently moves on to economic integration, social integration, political integration, and military integration. However, as the political confrontation in the Korean peninsula has already been well-researched elsewhere, We discuss economic issues which are likely to present themselves during the unification process. Economic issues, rather than the political ones, could prove to be of the greatest concern to a smooth reunification between the peninsula's long- divided neighbors.