Identifying influential and susceptible members of social networks

Identifying social influence in networks is critical to understanding how behaviors spread. We present a method that uses in vivo randomized experimentation to identify influence and susceptibility in networks while avoiding the biases inherent in traditional estimates of social contagion. Estimation in a representative sample of 1.3 million Facebook users showed that younger users are more susceptible to influence than older users, men are more influential than women, women influence men more than they influence other women, and married individuals are the least susceptible to influence in the decision to adopt the product offered. Analysis of influence and susceptibility together with network structure revealed that influential individuals are less susceptible to influence than noninfluential individuals and that they cluster in the network while susceptible individuals do not, which suggests that influential people with influential friends may be instrumental in the spread of this product in the network.     

Microcredit in theory and practice: using randomized credit scoring for impact evaluation

Microcredit institutions spend billions of dollars fighting poverty by making small loans primarily to female entrepreneurs. Proponents argue that microcredit mitigates market failures, spurs micro-enterprise growth, and boosts borrowers' well-being. We tested these hypotheses with the use of an innovative, replicable experimental design that randomly assigned individual liability microloans (of $225 on average) to 1601 individuals in the Philippines through credit scoring. After 11 to 22 months, we found evidence consistent with unmet demand at the current price (a roughly 60% annualized interest rate): Net borrowing increased in the treatment group relative to controls. However, the number of business activities and employees in the treatment group decreased relative to controls, and subjective well-being declined slightly. We also found little evidence that treatment effects were more pronounced for women. However, we did find that microloans increase ability to cope with risk, strengthen community ties, and increase access to informal credit. Thus, microcredit here may work, but through channels different from those often hypothesized by its proponents.     

扶贫与社会性别平等——世界宣明会榕江县"儿童为本,小区扶贫"项目案例的启示和思考

关注妇女的需求,强调妇女的参与,进而关注社会性别关系是提高扶贫效益的一个重要方面。对世界宣明会贵州省榕江县"儿童为本,小区扶贫"项目进行调研,通过项目中的几个案例,对其中的扶贫与妇女发展、扶贫与社会性别平等进行分析,为反贫困工作提供借鉴和参考。     

HIV decline associated with behavior change in eastern Zimbabwe

Few sub-Saharan African countries have witnessed declines in HIV prevalence, and only Uganda has compelling evidence for a decline founded on sexual behavior change. We report a decline in HIV prevalence in eastern Zimbabwe between 1998 and 2003 associated with sexual behavior change in four distinct socioeconomic strata. HIV prevalence fell most steeply at young ages-by 23 and 49%, respectively, among men aged 17 to 29 years and women aged 15 to 24 years-and in more educated groups. Sexually experienced men and women reported reductions in casual sex of 49 and 22%, respectively, whereas recent cohorts reported delayed sexual debut. Selective AIDS-induced mortality contributed to the decline in HIV prevalence.     

Use of oral contraception in the United States, 1965. In only 5 years oral contraception has become a major means of regulating fertility

This is the first report from the Na-tional Fertility Study, 1965, a survey of the reproductive behavior of a national sample of married women, under the age of 55, living with their husbands. The report presents basic data on the use of oral contraception by women under the age of 45, in relation to age, parity, education, race, and religion. The study leads to certain conclusions, as follows. Present, past, and prospective use vary inversely with the age of the woman and directly with the number of years of schooling; the majority of young women with college training have already used the oral contraceptive. Use by Negroes is somewhat less extensive than use by whites, particularly for ages below 25; some of this difference is explainable by concomitant racial differences in educational level. Negroes seem less likely than whites to use oral contraception for timing early births, and more likely, when they do use it, to be attempting to terminate their fertility. The same observation holds for white Catholics in relation to white non-Catholics. Although the extent of use may be lower among Catholics than non-Catholics, the proportion of Catholics who report use is substantial indeed in view of the persisting theological controversy. The prospects for increased use of oral contraception seem very good at present, but they may be limited by further developments in the technology of fertility regulation. Meanwhile the birth rate has declined substantially. Although much sophisticated analysis of other data from the survey will be required to determine the extent of the contribution of oral contraception to this decline, the findings presented here suggest that the contribution is substantial for young married couples. The major effect on the couple's eventual number of children may be less than the effect on the time pattern of childbearing; in any event, both lower eventual parity and delayed fertility contribute to a decline in the numbers of births from year to year. Whatever the intent may be, it is apparent that young American couples have adopted a new means for achieving their reproductive goals.     

AIDS in a new millennium

As we enter the new millennium the world is still facing the challenge of responding to the AIDS pandemic. A new report from the Joint United Nations Programme on HIV/AIDS presents the latest statistics on prevalence, spread, and impact of the disease. In their Perspective, Schwartl?nder and his colleagues discuss the newly released statistics and the strategies needed to combat the further spread of HIV/AIDS and to reduce prevalence in the most severely affected countries.     

She works hard for the money: women in Kansas agriculture

Since 1997 there has been a significant increase in the number and percentage of Kansas farmers who are women. Using Reskin and Roos’ (Job queues, gender queues: explaining women’s inroads into male occupations, Temple University Press, Philidelphia, 1990) model of “job queues and gender queues” I analyze changes in the agricultural industry in Kansas that resulted in more women becoming “principal farm operators” in the state. I find there are three changes largely responsible for women increasing their representation in the occupation: an increase in the demand for niche products, a decrease in the average farm size, and greater societal acceptance of women as farmers. This study adds to the growing literature on women principal farm operators in developed countries, and is among the first to explore why women are becoming a larger percentage of the occupation in the United States.     

The mother of all HIV challenges

AIDS researchers are finding cheaper and simpler ways to slow the spread of HIV from mother to child, and more pregnant women, even in the poorest countries, have access to anti-HIV drugs and formula--thanks to the largesse of donors, discounts from industry, new trade laws, and the tenacity of individual clinicians. But just as researchers offer ways to clear one enormous hurdle--drug availability--they run smack into other ones, ranging from social stigmas that discourage testing to disinterest on the part of cash-strapped health authorities to a deeply ingrained culture of breast-feeding--often supported by government policy for otherwise sound health reasons.     

Migration and Western europe: the old world turning new

The 1960s meant a historical turn of Western Europe, becoming an immigration area. Net immigration has been concentrated to some of the prosperous Western European countries and has been mainly determined by the demand of their particular national labor regimes. The size of alien employment has been very differently affected by the 1973 crisis, but a multiethnical society will remain a novel feature of most Western European countries. Political abdication from full employment and technological change makes a ghetto of un(der)employment a likely prospect of a large part of the second generation of recent immigrants into Western Europe.     

"外嫁女"土地拆迁补偿纠纷及其解决路径

在村规民约的背景下,就"外嫁女"的土地拆迁补偿的纠纷进行了探讨,在确立集体经济组织成员资格认定的基础上,在民间法(村规民约)与法律发生冲突时,提出了社会治理合法化的应对措施。     

绿色生产目标下家庭农场的社会化服务偏好及异质性分析——基于选择实验方法

为研究绿色生产目标下家庭农场的社会化服务需求,采用选择实验法(CE)和随机参数模型(RPL)分析了家庭农场的社会化服务偏好及异质性来源.结果表明:1)5类服务均能增加家庭农场参与绿色生产方案的效用水平,具体排序为:绿色技术指导＞绿色产品收购＞绿色信贷支持＞绿色农资供应＞绿色农机服务,在上述服务下,家庭农场意向的绿色生产...     

Population-level HIV declines and behavioral risk avoidance in Uganda

Uganda provides the clearest example that human immunodeficiency virus (HIV) is preventable if populations are mobilized to avoid risk. Despite limited resources, Uganda has shown a 70% decline in HIV prevalence since the early 1990s, linked to a 60% reduction in casual sex. The response in Uganda appears to be distinctively associated with communication about acquired immunodeficiency syndrome (AIDS) through social networks. Despite substantial condom use and promotion of biomedical approaches, other African countries have shown neither similar behavioral responses nor HIV prevalence declines of the same scale. The Ugandan success is equivalent to a vaccine of 80% effectiveness. Its replication will require changes in global HIV/AIDS intervention policies and their evaluation.     

马卡连柯的家庭道德教育思想及其启示

马卡连柯是前苏联著名的教育家,他在晚年特别重视家庭道德教育问题。马卡连柯的家庭道德教育思想主要体现在:及早对儿童进行道德教育;父母必须以身作则、起表率作用;通过家庭生活制度培养孩子良好的行为习惯;建立良好的家风;从身边小事做起,重视细节;对孩子的教育要做到严慈、奖惩结合等。马卡连柯的家庭道德教育思想对我国未成年人道德建设有深刻的启示:重视家庭在未成年人道德建设中的基础性作用;发挥父母在家庭道德教育中的主导作用;为孩子营造一个良好的家庭道德氛围;未成年人道德建设要从娃娃抓起,及早实施;从基本道德素质抓起,从规范行为习惯做起,培养未成年人良好的道德品质和文明行为等。     

罗非鱼产业标准化现状及分析

目前全球有100多个国家和地区开展罗非鱼养殖,年产量已超过200万吨。近十年来我国的罗非鱼产量以平均每年9%左右的速度递增,居世界第一,是我国优势出口水产品之一。为了了解罗非鱼产业标准化现状,调查现行标准在这个行业的适用性,利用到广东、广西和海南等罗非鱼主产区进行实地走访、资料收集和发放调查表等调研手段,考察了我国罗非鱼生产、流通全过程。了解了养殖水质、种质、鱼苗及亲本、饲料选择与投喂、病害防治与用药、运输装备的清洁卫生及加工与包装存在着的潜在危害。研究了现行标准实际应用情况,利用对比和分析的方法梳理了缺失及需要修订的标准。在分析和研究了先进国家所采用的健康养殖和水产品质量安全标准的前提下,结合我国罗非鱼产业实际需求和科研现状,建议制定4项标准,修订6项标准,为规范罗非鱼产业的健康发展提供保障。     

从中国农民素质和农民需求现状看农村家政推广的必要性

农村家政推广是满足农民对生活的多方位、多层次需求的重要途径,是提高我国农民素质（尤其是促进农村妇女发展）、建设现代新型农民家庭,从而构建社会主义新农村的有效手段。针对我国农村家政推广事业的现状,建议国家要赋予政府公益性农业推广体系家政推广的职能;将家政教育课程纳入国民教育体系和内容;加强对农村妇女的家政培训;加强舆论宣传,营造社会氛围,走出＂狭义家政＂和社会上对家政误解的圈子。     

基于ELES模型的我国农村居民消费动态分析

以中国统计年鉴为基础,利用扩展线性支出系统(ELES)模型,并借助SPSS13.0统计软件,对2002—2009年我国农村居民各项消费的边际消费倾向、需求收入弹性、基本需求进行了动态分析。结果表明,我国农村居民各项消费支出与纯收入之间存在显著的线性相关关系;农村居民边际消费倾向较低,且呈下降趋势,其中食品、居住分别稳居第1、2位,交通通讯与文教娱乐分别位居第3、4位;交通通讯收入弹性最高,其次是居住,文教娱乐的收入弹性在2009年跃居第2位,且呈增加趋势;农村低收入户尚未满足基本需求,收入差距在进一步扩大,且农村居民在满足基本需求后,用于提高生活质量的消费比例在不断下降。     

日粮中添加微生态制剂对瘦肉型繁殖母猪生产性能的影响

为探讨微生态制剂对母猪繁殖性能和仔猪生长性能的影响,选择同期配种的长×大二元杂种健康母猪20头,随机分为对照组和试验组2组(每组10头),对照组饲喂基础日粮,试验组在基础日粮基础上添加酵母菌制剂0.1%(活菌数1.7×106cfu/g)、乳酸菌制剂0.1%(活菌数2.0×106cfu/g)和枯草芽孢杆菌制剂0.1%(活菌数1.1×106cfu/g),进行1个繁殖周期(怀孕到仔猪断奶)135d的对比饲养试验。结果表明:试验组窝均产仔数11.10头,窝均产活仔数10.50头,分别比对照提高12.61%(P>0.05)和10.48%(P<0.05);仔猪初生窝重15.523kg,平均个体重1.511kg,分别比对照提高17.48%(P>0.05)和5.76%(P<0.05);仔猪平均断奶窝重49.169kg,平均断奶个体重5.096kg,分别比对照提高32.89%(P>0.05)和16.90%(P>0.05)。试验组仔猪死胎率2.8571%、弱仔率6.306 3%、断奶死亡率4.610%,分别比对照降低0.334 4%(P>0.05)、0.910 2%(P>0.05)和3.35%(P>0.05)。结论:在日粮中添加微生态制剂可提高母猪的繁殖能力与仔猪的生长力,降低仔猪的死亡率。     

1971-2015年烟台冬小麦不同生育期温度变化

旨在分析不同生育期温度变化对冬小麦的影响，基于1971—2015年烟台平均气温资料，利用线性倾向率和M-K检验，分析气温的年际变化趋势、年代变化率和突变点。结果表明：烟台冬小麦全生育期、营养生长期、营养生长和生殖生长并生期（并生期）和生殖生长期温度均明显增加，线性倾向率依次为0.15℃/10 a(P<0.01)、0.12℃/10 a(P<0.05)、0.21℃/10 a(P<0.01)和0.28℃/10 a(P<0.01)；营养生长期、并生期和生殖生长期、全生育期平均温度的变异系数依次为17.27%、11.80%、3.94%、8.05%；营养生长期、并生期、生殖生长期、全生育期的突变年份分别出现在1987年、1991年、1981年、1982年。温度升高会导致冬小麦难以通过春化，花芽分化期缩短，生殖生长期遭遇初夏干热风等灾害性天气影响，最终造成小麦减产。在全球变暖背景下，应顺应气候变化，合理搭配冬小麦品种和采取相应管理措施，以促进烟台农业高产高质地可持续发展。     

Values and policy conflict in West German agriculture

Family farming became a major social force in the Federal Republic following World War II. Several political, economic and social factors facilitated the development of a unified political representation within the farm sector. The German Farmers Union (Deutscher Bauernverband) became the main representative of the farm sector. Its platform included the preservation of family farms and it attempted to realize this goal through the promotion of commodity price support policies. Political support for these programs was legitimized with the elaboration of a system of values espousing the positive qualities of family farms. Price support policies were opposed by free market advocates with an alternative system of values that fundamentally contradicted those of family farm advocates. Although commodity price supports promoted by partisans of family farming dominated agricultural policy formation in the 1950s and 1960s, fiscal crisis in the EEC and economic differentation within the farm sector began to undermine the position of family farming as a social force. But economic stagnation also prevented the free market position from gaining dominance. Economic differentiation within the farm sector has had an important regional dimension, and this has served as a basis for policy compromise. Economic changes over the post-WWII period have undermined the family farm as a social force. Nevertheless, values associated with family farming continue to have a place in agricultural policy. However, family farming is valued less as an end in itself, and more as a means to the realization of more practical ends such as the preservation of rural landscapes for recreational purposes.     

鲁西南地区青山羊生产性能和繁殖性能研究

在收集鲁西南当地畜牧部门的养殖、育种资料及相关养殖场的原始记录基础上,采用普查与抽样调查相结合的方式,对鲁西南地区18个县(市)、5个区的青山羊地方品种的生产、繁殖性能进行了调查,结果表明6月猾子皮质量最好;青山羊成年板皮的面积接近波尔山羊;青山羊平均窝产2.82只,成活率达91%。