The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,...The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,which posits that the stock market is micro efficient,but macro inefficient.I develop a new model to measure potential inefficiency at macro level.Inefficiency in price(P)is driven by earnings(EPS)and/or valuation(P/E).At the peak of the TMT-bubble in 1999/2000,both factors were in play,while only earnings assumptions were inefficient before the Great Financial Crisis in 2008/09.The model developed show expected results in terms of relative efficiency for Developed vs.Emerging Markets and for Dow Jones vs.Nasdaq.Parts of academia seems to accept a different definition of market efficiency at micro level compared to macro level.At macro level,a standard“price vs.fair value”definition seems to be generally accepted,while at micro level,a relative“price vs.price”definition seems to be broadly used.The latter way of thinking has historically contributed to price bubbles.Numerous examples of stock prices that deviate significantly from their fair value in days,weeks and months and doubtful methods for measuring efficiency at micro level cast doubt about the micro efficiency claim part of Samuelson’s Dictum.展开更多
"Samuelson's Concern" and "Kindleberger Trap" are cited as justifications for trade protectionism under the Trump administration. After reviewing Samuelson's and Kindleberger's trade th..."Samuelson's Concern" and "Kindleberger Trap" are cited as justifications for trade protectionism under the Trump administration. After reviewing Samuelson's and Kindleberger's trade theories, this paper finds that both Samuelson and Kindleberger are actually proponents of free trade, and that their common concern is falling US competitiveness due to its economic model, domestic institutional rules, and unilateralism. Both the "Samuelson's Concern" and "Kindleberger Trap" are distortions of Samuelson's and Kindleberger's original theories and the arguments' defense of protectionism cannot overcome the challenges confronting the U.S. and will destabilize international economic order.展开更多
为精准识别与分类不同花期杭白菊,满足自动化采摘要求,该研究提出一种基于改进YOLOv8s的杭白菊检测模型-YOLOv8s-RDL。首先,该研究将颈部网络(neck)的C2f(faster implementation of CSP bottleneck with 2 convolutions)模块替换为RCS-O...为精准识别与分类不同花期杭白菊,满足自动化采摘要求,该研究提出一种基于改进YOLOv8s的杭白菊检测模型-YOLOv8s-RDL。首先,该研究将颈部网络(neck)的C2f(faster implementation of CSP bottleneck with 2 convolutions)模块替换为RCS-OSA(one-shot aggregation of reparameterized convolution based on channel shuffle)模块,以提升骨干网络(backbone)特征融合效率;其次,将检测头更换为DyHead(dynamic head),并融合DCNv3(deformable convolutional networks v3),借助多头自注意力机制增强目标检测头的表达能力;最后,采用LAMP(layer-adaptive magnitude-based pruning)通道剪枝算法减少参数量,降低模型复杂度。试验结果表明,YOLOv8s-RDL模型在菊米和胎菊的花期分类中平均精度分别达到96.3%和97.7%,相较于YOLOv8s模型,分别提升了3.8和1.5个百分点,同时权重文件大小较YOLOv8s减小了6 MB。该研究引入TIDE(toolkit for identifying detection and segmentation errors)评估指标,结果显示,YOLOv8s-RDL模型分类错误和背景检测错误相较YOLOv8s模型分别降低0.55和1.26。该研究为杭白菊分花期自动化采摘提供了理论依据和技术支撑。展开更多
文摘The stock market in the form of the S&P 500 is estimated to be inefficient in 13%to 30%of the time since 1963.This is contrary to the theory of efficient capital markets,but in accordance with Samuelson’s Dictum,which posits that the stock market is micro efficient,but macro inefficient.I develop a new model to measure potential inefficiency at macro level.Inefficiency in price(P)is driven by earnings(EPS)and/or valuation(P/E).At the peak of the TMT-bubble in 1999/2000,both factors were in play,while only earnings assumptions were inefficient before the Great Financial Crisis in 2008/09.The model developed show expected results in terms of relative efficiency for Developed vs.Emerging Markets and for Dow Jones vs.Nasdaq.Parts of academia seems to accept a different definition of market efficiency at micro level compared to macro level.At macro level,a standard“price vs.fair value”definition seems to be generally accepted,while at micro level,a relative“price vs.price”definition seems to be broadly used.The latter way of thinking has historically contributed to price bubbles.Numerous examples of stock prices that deviate significantly from their fair value in days,weeks and months and doubtful methods for measuring efficiency at micro level cast doubt about the micro efficiency claim part of Samuelson’s Dictum.
文摘"Samuelson's Concern" and "Kindleberger Trap" are cited as justifications for trade protectionism under the Trump administration. After reviewing Samuelson's and Kindleberger's trade theories, this paper finds that both Samuelson and Kindleberger are actually proponents of free trade, and that their common concern is falling US competitiveness due to its economic model, domestic institutional rules, and unilateralism. Both the "Samuelson's Concern" and "Kindleberger Trap" are distortions of Samuelson's and Kindleberger's original theories and the arguments' defense of protectionism cannot overcome the challenges confronting the U.S. and will destabilize international economic order.
文摘为精准识别与分类不同花期杭白菊,满足自动化采摘要求,该研究提出一种基于改进YOLOv8s的杭白菊检测模型-YOLOv8s-RDL。首先,该研究将颈部网络(neck)的C2f(faster implementation of CSP bottleneck with 2 convolutions)模块替换为RCS-OSA(one-shot aggregation of reparameterized convolution based on channel shuffle)模块,以提升骨干网络(backbone)特征融合效率;其次,将检测头更换为DyHead(dynamic head),并融合DCNv3(deformable convolutional networks v3),借助多头自注意力机制增强目标检测头的表达能力;最后,采用LAMP(layer-adaptive magnitude-based pruning)通道剪枝算法减少参数量,降低模型复杂度。试验结果表明,YOLOv8s-RDL模型在菊米和胎菊的花期分类中平均精度分别达到96.3%和97.7%,相较于YOLOv8s模型,分别提升了3.8和1.5个百分点,同时权重文件大小较YOLOv8s减小了6 MB。该研究引入TIDE(toolkit for identifying detection and segmentation errors)评估指标,结果显示,YOLOv8s-RDL模型分类错误和背景检测错误相较YOLOv8s模型分别降低0.55和1.26。该研究为杭白菊分花期自动化采摘提供了理论依据和技术支撑。
