农民养老问题亟待解决

农村现行的家庭养老、土地养老、集体养老正在弱化,巩固家庭养老的基础地位,强化土地保障功能,辅之以社区扶持,推行多层次养老保险,符合中国国情和农村生产力发展水平,是解决农村养老问题的必然选择.     

Private borrowing during the financial revolution: Hoare's Bank and its customers, 1702–241

The financial revolution improved the British government's ability to borrow, and thus its ability to wage war. North and Weingast argued that it also permitted private parties to borrow more cheaply and widely. We test these inferences with evidence from a London bank. We confirm that private bank credit was cheap in the early eighteenth century, but we argue that it was not available widely. Importantly, the government reduced the usury rate in 1714, sharply reducing the circle of private clients that could be served profitably.     

Hedging,Financing and Investment Decisions: A Simultaneous Equations Framework

We empirically investigate the interactions among hedging, financing, and investment decisions. We argue that the way in which hedging affects a firm's financing and investing decisions differs for firms with different growth opportunities. We find that high growth firms increase their investment, but not leverage, by hedging. However, we also find that firms with few investment opportunities use derivatives to increase their leverage.     

Mining and Social Movements: Struggles Over Livelihood and Rural Territorial Development in the Andes

Social movements have been viewed as vehicles through which the concerns of poor and marginalized groups are given greater visibility within civil society, lauded for being the means to achieve local empowerment and citizen activism, and seen as essential in holding the state to account and constituting a grassroots mechanism for promoting democracy. However, within development studies little attention has been paid to understanding how social movements can affect trajectories of development and rural livelihood in given spaces, and how these effects are related to movements’ internal dynamics and their interaction with the broader environment within which they operate. This paper addresses this theme for the case of social movements protesting contemporary forms of mining investment in Latin America. On the basis of cases from Peru and Ecuador, the paper argues that the presence and nature of social movements has significant influences both on forms taken by extractive industries (in this case mining) and on the effects of this extraction on rural livelihoods. In this sense, one can usefully talk about rural development as being co-produced by movements, mining companies, and other actors, in particular the state. The terms of this co-production, however, vary greatly among different locations, reflecting the distinct geographies of social mobilization and of mineral investment, as well as the varying power relationships among the different actors involved.     

Through Trial and Error to Collusion*

In this article we study a very simple trial and error learning process in the context of a Cournot oligopoly. Without any knowledge of the payoff functions players increase, respectively decrease, their quantity as long as this leads to higher profits. We show that despite the absence of any coordination or punishing device this process converges to the joint‐profit‐maximizing outcome.     

江苏居民收入分配差距及其治理分析

改革开放以来,江苏居民收入普遍提高,人民生活得到很大改善,但近年来居民收入开始出现差距并且日益扩大,已成为影响社会稳定和经济发展的重要问题。文章首先分析了江苏居民收入分配的现状,然后剖析了影响居民收入分配差距过大的成因,在此基础上提出了防止居民收入差距过大的治理对策。     

混合拉曼/EDFA放大器及其在DWDM中的应用

本文综述了混合拉曼／掺饵光纤放大器（HFA）的工作原理，结构和特点，介绍了4类HFA基本结构及其实验结果，并通过介绍近年来各类HFA在密集波分复用（DWDM）系统中的应用表明了HFA在带宽，增益和噪声特性方面的优点。     

A theoretical framework to evaluate different margin‐setting methodologies

The margin system is the first line of defense against the default risk of a clearinghouse. From the perspectives of a clearinghouse, the utmost concern is to have a prudential system to control the default exposure. Once the level of prudentiality is set, the next concern will be the opportunity cost of the investors, because high opportunity cost discourages people from hedging futures, and thus defeats the function of a futures market. In this article, we first develop different measures of prudentiality and opportunity cost. We then formulate a statistical framework to evaluate different margin‐setting methodologies, all of which strike a balance between prudentiality and opportunity cost. Three margin‐setting methodologies, namely, (1) using simple moving averages; (2) using exponentially weighted moving averages; (3) using a GARCH approach, are applied to the Hang Seng Index futures. Keeping the same prudentiality level, it is shown that the one using a GARCH approach by and large gives the lowest average overcharge. © 2004 Wiley Periodicals, Inc. Jrl Fut Mark 24:117–145, 2004