农业绿色全要素生产率测度及收敛性分析——基于碳汇和碳排放双重视角CSSCI

对农业绿色全要素生产率进行科学合理的测度有助于精准把握农业碳减排潜力。本文基于2000—2019年我国省际面板数据,分别从碳汇和碳排放两个角度测度农业绿色全要素生产率,并进行了空间收敛性分析。结果表明:(1)考察期内农业绿色全要素生产率年均增速为1.1%,农业技术进步是其增长的主要动因;(2)农业绿色全要素生产率在时空演化过程中具有差异性和阶段化特征;(3)农业绿色全要素生产率呈现显著正向空间关联性,且逐渐强化,农业绿色全要素生产率较低地区发展速度要高于农业绿色全要素生产率较高地区,区域差异正在减小。研究结果对于精准评判农业碳减排潜力和碳吸收能力、实现“双碳”目标具有参考意义。     

Inefficiency of strategy-proof allocation mechanisms in pure exchange economies

In this paper I prove that in the standard model of 2×n (n2) pure exchange economies there is no allocation mechanism that is efficient, non-inversely-dictatorial, and strategy-proof. This strengthens two previous results on this subject by Hurwicz and by Dasgupta, Hammond, and Maskin.I thank Alvin Klevorick, William Thomson, and an anonymous referee of the journal for many helpful comments.     

Business restructuring,management control,and corporate organization

Conclusions After half a century of growing dominance of the large corporation by non-owning managers, the 1980s were marked by a slowing or even reversing of their quiet revolution. Professional managers had come to control the corporation on the premise that they could more efficiently produce shareholder value than the original founder-owners. They turned shareholding into a passive investment on the same premise. As companies faced increasingly competitive pressures during the 1980s, however, the legitimacy of the rule of incumbent management came under challenge. No longer could government interference be blamed for many of the problems facing business; fingers pointed at management itself. As the criticism of corporate leadership gathered momentum, a leading diagnosis focused on one of managerial capitalism's crowning achievements: the autonomous power of professional management.The critique viewed the managerial autonomy as excessively permissive, the agency system as no longer effective. Professional managers had come to show too much concern for the social welfare of various stakeholder groups, including themselves, and too little concern for the financial welfare of the only stakeholder group that should really count — the shareholders. Many of the restructuring efforts were thus undertaken in the name of returning companies to the single-minded pursuit of ownership interests. What had stood in the way of such a pursuit was less a matter of government constraint and more a matter of inadequate stockholder vigilance by their appointed agents.Mindful of the critique, incumbent managements moved during the mid- to late-1980s to improve stockholder returns by paring the workforce and cutting other costs. Corporate acquisitions and leveraged buyouts brought new management teams to the fore where others had seemingly fallen short. The resulting restructuring reached a large proportion of the nation's major companies. Half or more of the largest companies had undergone a significant reduction in their workforce. And the dollar value of company resources changing ownership hands expanded considerably. The aggregate purchase price of mergers and acquisitions of publicly-traded firms in 1988 was nearly three times greater than in 1981. Even more striking was the sharp increase in the number of publicly-traded companies and divisions that were taken private. The aggregate dollar value of such buyouts in 1988 had increased almost 25 times over that in 1981. This opening of the market for corporate control among major U.S. firms brought a significant fraction of the nation's large corporations more directly under the immediate oversight of ownership interests.The reassertion of ownership control over large corporations was usually taken in the name of improving corporate earnings. Would be takeover groups generally promised more internal discipline and stronger financial performance. Whatever the actual financial impact of the intensification of ownership interests, available research suggests that it has had organizational impact. General company strategies may come to be more centrally guided while specific operating actions are devolved further down the organization.Ownership change and other restructuring steps have also ramified into corporate social and political action. That outreach is likely to be less vigorous and more divided. It is also being redirected. During the 1970s and early 1980s, corporate energies focused on reducing government regulation and improving community opinion. Those energies are now increasingly focused on facilitating or resisting restructuring. Companies have fought legislation that would limit the process of plant closings, but they have also sought legislation to protect themselves against hostile takeovers.The evidence also suggests that considerable managerial discretion remains in shaping company response to the restructuring pressures. Although market and organizational factors are sure to act as constraints, top management, whether a relatively autonomous non-owning management group or an owner-dominated management, retains an important independent capacity to exercise strategic choice. That choice is likely to receive special shaping by the long-term ascendance of financial managers and the decline of manufacturing personnel at the executive level.Yet corporate change must not be viewed as isolated managerial responses to changing market conditions. Companies and managements frequently look to one another for guidance in coping with ambiguous circumstances. DiMaggio and Powell's analysis of organizational isomorphism, for example, suggests that firms frequently adopt organizational practices not because they are dictated by the firm's market strategies, but rather because they are already used by other companies. Similarly, Granovetter's analysis of the social embeddedness of economic action indicates that company decisions are partially shaped by top management's contacts with their counterparts in other firms. Understanding company responses to restructuring pressures therefore requires a focus on inter-company flows of ideas and doctrines as well as purely internally generated responses specific to the company. Reactions to the restructuring pressures that are collectively developed and defined in the broader business community may prove to be as critical as individually fashioned solutions in guiding management approaches to restructuring during the years to come.

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Zeroing in on leadership effectiveness: The methodological challenges of benchmarking leadership practices

Business success in the 21st century will be based on the widespread mastery of leadership roles, rather than on the directives of a professional or leadership elite. The first step for systematically enacting a leadership development agenda for our nation is to identify the factors, values or qualities most important to leadership effectiveness. Next, we must improve our understanding of how these guiding ideas and insights translate into what successful leaders do. As we perfect this understanding, we will need to operationally define the best practices of successful leaders. These best practices must then become benchmarks for intensive leadership development efforts.This article considers nine methodological challenges of the first agenda item-identification of the factors, values or qualities most important to leadership effectiveness. To illustrate these challenges, the authors use their own business leadership research as a case study. This research surveys 127 chairmen, chief executive officers, and presidents-a cross section of successful U.S.A. business leaders, including men and women from all parts of the nation who have diverse industry, racial, ethnic and religious backgrounds. The authors identify where methodological improvements are needed to cope with the challenges of leadership research. They suggest important directions for methodological development and propose three minimum standards for future leadership research.     

再谈四川盆地小麦品种产量性状的育种目标

用近10年的小麦区试资料,从粒重的角度将四川麦区小麦品种分为“大粒型”（千粒重50g左右）、“中间型”（千粒重45g左右,穗粒数40粒左右）和“粒数型”（千粒重40g左右,稳粒数50粒以上）三类,通过相关及因子分析表明：我省推广小麦品种大多属“中间型”,该类品种丰产性、稳产性及商品性都较优良;“粒数型”品种的丰产性和稳产性在三类品种中最好但粒重较小,商品性欠佳;而“大粒型”品种对环境适应性较差,不利高产稳产。四川小麦育种宜采用“中间型”或“粒数型”路线,特别是产量水平要有所突破,更须走“粒数型”的路子。     

小麦新品种“绵阳26”主要性状与产量的关系

对45个试验点的资料分析,多抗、丰产、优质、广适小麦新品种绵阳26的主要性状有效穗x1、穗粒数x2和千粒x3、单穗重x4与产量y的回归方程为：y＝－614．8425＋9.8683x1＋7.3223x2＋10．5315x3＋22．5748x4。经偏回归和偏相关分析,产量构成因素中,千粒重、有效穗对绵阳26产量的贡献和影响最大（b'3＝1．7435,b'1＝1．5372,R3y.＝0．7983,R1y＝0．6991）。在现有产量的基础上稳定千粒重,主攻穗数和穗粒数,是发挥绵阳26高产潜力的决定因素。     

Community,Family, and Race/Ethnic Differences in Health Status in Rural Areas1

Abstract Many race-specific differences in health outcomes that have been observed in previous research have been attributed to class and racebased group differences which either facilitate or constrain health opportunities and behaviors. These include such variables as different rates of poverty, health insurance coverage, and access to medical care. However, these relationships have been inadequately examined in rural communities where minority status may be even more detrimental to health than in urban areas, due to various constraints on access to health care. We present an analysis that assesses the effects of community, family structure, sociodemographic, and medical care variables on self-reported health status among Hispanics, Mrican Americans, and non-Hispanic whites in six rural communities in Florida. Community structural characteristics had a significant effect on self-reported health, as did some of the measures of how respondents “experience” community. These relationships held even when other sets of variables were added to the models. Family/household characteristics and sociodemographic and medical care variables were less important in explaining self-reported health status. These findings suggest that community continues to be important in explaining differences in health status in rural areas.