频率不受运放参数影响的文氏桥振荡器

本文介绍一组（12个）新的正弦振荡器，这组振荡器使用两个运算放大器，其振荡频率不受单极点有源元件增益带宽之积的影响。这种特性是由本文所介绍的电路结构取得的，即不需要调节。     

Do Institutions Cause Growth?

We revisit the debate over whether political institutions cause economic growth, or whether, alternatively, growth and human capital accumulation lead to institutional improvement. We find that most indicators of institutional quality used to establish the proposition that institutions cause growth are constructed to be conceptually unsuitable for that purpose. We also find that some of the instrumental variable techniques used in the literature are flawed. Basic OLS results, as well as a variety of additional evidence, suggest that (a) human capital is a more basic source of growth than are the institutions, (b) poor countries get out of poverty through good policies, often pursued by dictators, and (c) subsequently improve their political institutions.     

Growth in regions

We use a newly assembled sample of 1,528 regions from 83 countries to compare the speed of per capita income convergence within and across countries. Regional growth is shaped by similar factors as national growth, such as geography and human capital. Regional convergence rate is about 2 % per year, comparable to that between countries. Regional convergence is faster in richer countries, and countries with better capital markets. A calibration of a neoclassical growth model suggests that significant barriers to factor mobility within countries are needed to account for the evidence.     

Social Movements and Public Administration: Spontaneous Citizens’ Committees in Florence

Urban protest is often carried out by citizens’ committees: that is, political groups that mobilize on issues affecting a small territorial area, use various forms of protest, and are organized in very loosely structured forms. Based on interviews with members of citizens’ committees in Florence, this article discusses their identities, strategies and organizational models, as well as their interaction with local authorities. Active mainly in issues of pollution and security, the Florentine committees frame their demands in terms of defending or improving quality of life in a defined territory. Mobilizing citizens who have often had previous experience in voluntary and/or political associations, citizens’ committees evidence a strongly participatory organizational model, with, however, notably discontinuous levels of activity. Whilst privileging moderate forms of protest, citizens’ committees also seem to have more and more channels of access to the institutions of local government, which sometimes perceive them as a source of information and aggregate consensus. The quality of the interactions between citizens’ committees and the public administration plays an important role in determining the extent to which this type of urban protest produces social capital. La contestation urbaine est souvent menée par des comités citoyens, c’est–à–dire des groupes politiques qui se mobilisent sur des problèmes affectant une zone territoriale limitée, emploient diverses formes de protestation et s’organisent selon des structures très informelles. A partir d’entretiens avec des membres de comités citoyens de Florence, cet article étudie leurs identités, stratégies et modèles d’organisation, ainsi que leur interaction avec les autorités locales. Surtout actifs sur des questions de pollution et de sécurité, les comités florentins formulent leurs revendications en termes de défense ou d’amélioration de la qualité de la vie dans un territoire donné. Mobilisant les citoyens qui, souvent, ont déjà eu une expérience dans des associations bénévoles et/ou politiques, ces comités démontrent un modèle organisationnel fortement participatif avec, toutefois, des degrés d’activité particulièrement intermittents. Bien que privilégiant des formes modérées de contestation, les comités citoyens semblent disposer de moyens toujours plus nombreux d’accéder aux institutions des gouvernements locaux, lesquelles les considèrent parfois comme une source d’informations et de consensus collectif. La qualité des interactions entre les comités citoyens et l’administration publique est importante si l’on veut déterminer dans quelle mesure ce type de contestation urbaine génère un capital social.     

Corporate Ownership Around the World

We use data on ownership structures of large corporations in 27 wealthy economies to identify the ultimate controlling shareholders of these firms. We find that, except in economies with very good shareholder protection, relatively few of these firms are widely held, in contrast to Berle and Means's image of ownership of the modern corporation. Rather, these firms are typically controlled by families or the State. Equity control by financial institutions is far less common. The controlling shareholders typically have power over firms significantly in excess of their cash flow rights, primarily through the use of pyramids and participation in management.     

The quality of government

We investigate empirically the determinants of the quality ofgovernments in a large cross-section of countries. We assessgovernment performance using measures of government intervention,public sector efficiency, public good provision, size of government,and political freedom. We find that countries that are poor,close to the equator, ethnolinguistically heterogeneous, useFrench or socialist laws, or have high proportions of Catholicsof Muslims exhibit inferior government performance. We alsofind that the larger governments tend to be the better performingones. The importance of (reasonably) exogenous historical factorsin explaining the variation in government performance acrosscountries sheds light on the economic, political, and culturaltheories of institutions.     

Retail-center viability and urban form: a micro analysis

Location is commonly axiomatically stated as the most important real estate feature. However, little attention is given to the urban system that reveals how location is configured, and how that configuration sustains the viability of site-specific retailing activity in the metropolitan region. In this paper, we use block-level, GIS-aided spatial data that reveal the physical qualities of the retail center’s built environment as well as employment and business activity. Thereby, we examine a hypothesis that retailing viability is linked to urban form and set out to determine a statistical relationship. Retail sales data indicate the viability of businesses in two matched shopping centers, urban and suburban, each anchored by an identical big-box retailer downsized to a neighborhood supermarket, with pedestrian-friendly orientation and proximity to housing. The paper concludes with regression estimates of the urban form determinants of business viability by various distances from the retail center.     

Lombard Enlightenment and Classical Political Economy

Abstract

This paper discusses the formative steps of ‘Classical’ Political Economy under the joint influence of the Italian and Scottish Enlightenment. Pietro Verri is a leading figure of the Italian Enlightenment and he belongs to the Lombard branch of the Italian School of Political Economy (sometimes named ‘School of Milan’) during the latter half of the eighteenth century. Schumpeter's treatment of the ‘School of Milan’ describes Pietro Verri as ‘the most important pre-Smithian authority on Cheapness-and-Plenty’. A careful canvass of the texts substantiates Schumpeter's suggestion. Verri stands out as a key figure in the transition from Physiocracy to the Smithian system.