A note on the decomposition (at a point) of aggregate excess demand on the Grassmannian

This paper analyzes the properties of aggregate excess demand functions for economies with an arbitrary finite set of N commodities where agents face trading restrictions of a general, abstract form: their budget set is defined by K-dimensional planes in ^N. It is shown that, if there are at least K agents in the economy, the only general property satisfied by the value of aggregate excess demand and its derivative, at any arbitrary point, is Walras Law. The result is established by considering an economy where agents' preferences are of a ‘generalized Leontief' type.     

Drug testing and the law

This article examines judicial and administrative rulings and legislation involving or related to the issue of drug testing in the workplace. It discusses the rights of employees in the public and private sector: constitutional rights; federal, state, and local statutory rights; rights of unionized employees; and common law rights. It analyzes both the current state of the law and future directions the law may take, as courts and administrative agencies decide more cases and governmental bodies continue to pass drug testing legislation.     

等截面斜腿刚构桥的几何布局优化

以应力平方均值最小为优化目标，建立了跨越V形谷的等截面斜腿刚构桥在列车荷载和自重共同作用下的布局静力优化的数学模型，采用直接搜索法进行了设计变量的寻优。     

Abnormal trading volume,news and market efficiency: Evidence from the Jamaica Stock Exchange

This paper investigates market efficiency of the Jamaica Stock Exchange (JSE). Together, weak and semi-strong form efficiency claim that historical and newly released public information do not predict future stock price movement. We test both forms of market efficiency by analyzing stock price behavior during times of abnormal trading volume and around the release dates of earnings information. Abnormal trading volume may be driven by liquidity demand or reflect new or private information flow to the market. Using JSE data over the period 2000 to 2021, we find price dynamics consistent with price pressure as firms experience negative abnormal returns on the day of abnormal trading activity but offsetting positive abnormal stock returns on the following day. Further findings show post earnings announcement drift on the JSE. Taken as a whole, the evidence suggests violations of market efficiency and has implications for capital allocation in this emerging market.     

武汉市农贸市场超市化改造问题研究

武汉作为全国"农改超"先行的特大城市之一,经过两年多的实践与探索,"农改超"已初见成效,但仍存在市场主体利益关系复杂、超市生鲜食品营运成本较高、超市农业发展滞后、农产品物流配送体系不健全、制度环境不够宽松等制约因素.为此,需要调整利益关系格局、培育壮大生鲜经营主体、大力发展超市农业、构建现代农产品物流配送体系和营造"农改超"的良好环境.     

Multivariate volatility forecasts for stock market indices

Volatility forecasts aim to measure future risk and they are key inputs for financial analysis. In this study, we forecast the realized variance as an observable measure of volatility for several major international stock market indices and accounted for the different predictive information present in jump, continuous, and option-implied variance components. We allowed for volatility spillovers in different stock markets by using a multivariate modeling approach. We used heterogeneous autoregressive (HAR)-type models to obtain the forecasts. Based an out-of-sample forecast study, we show that: (i) including option-implied variances in the HAR model substantially improves the forecast accuracy, (ii) lasso-based lag selection methods do not outperform the parsimonious day-week-month lag structure of the HAR model, and (iii) cross-market spillover effects embedded in the multivariate HAR model have long-term forecasting power.     

Utility Regulation and Risk Allocation: The Roles of Marginal Cost Pricing and Futures Markets

The effects on consumer welfare of requiring a utility facing cost or demand risk to use either a fixed retail price or marginal cost pricing are assessed. With marginal cost pricing and cost volatility an efficient futures market allows consumer welfare to be at least as high in every state as with the fixed price. With demand risk marginal cost pricing can benefit the consumer in every state without harming the firm if the profit difference is transferred to the consumer. A futures market can act as a partial replacement for the transfer.     

Physical Search

Unidirectional search is an evolutionarily stable outcome in an economy where homogenous buyers and sellers can either move or stay. It is more efficient than bidirectional search. In unidirectional search, it is more efficient if the more numerous agents move and the less numerous agents stay, than vice versa.     

Unemployment insurance: The role of electoral systems and regional labour markets

Levels of insurance against unemployment vary considerably across countries. Replacement rates, the ratio relating income from unemployment to what people earned when they were employed, are higher in countries with proportional electoral systems than in countries with majoritarian systems. Also, replacement rates are positively correlated with per capita income and negatively correlated with the countries' unemployment rates. I develop an electoral competition model that replicates these stylized facts.     

The long-run effects of the real exchange rate on employment and wages in Canadian manufacturing

ABSTRACT

The literature on real exchange rate effects on the labour market is dominated by short-run analysis showing that there is heterogeneity in the responses of firms or industries to a real exchange rate shock. Analysing data on Canadian manufacturing industries, I conclude that there is a common long-run equilibrium across all manufacturing industries controlling for their openness to trade after varying adjustments to a real exchange rate shock have taken place. This conclusion is important from the perspective of policy making because it helps to form expectations about the effects of a real exchange rate movement on the labour market. The results suggest that real appreciation leads to economically significant reductions in employment in manufacturing in the long run. Real wages decrease in industries that are highly engaged in international trade and somewhat increase in industries that are relatively closed to international trade. Both employment and real wages converge quickly to the long-run equilibrium.