Health care economist Amy Finkelstein wins the Clark Award

Health care economist Amy Finkelstein wins the Clark Award
Exciting!
For details, pls see: http://www.aeaweb.org/aea/AmyFinkelstein.pdf

第一次被老板challenge

昨天在讨论上半学期学习的时候被老板第一次challenge，觉得很有启示。
联系理论一直是我的弱项，单纯做计量分析没什么了不起的，但是做的时候有经济的视角，并且联系经济理论才是有水平的表现阿：）
以此记，加油！

抗生素分级

提到头孢类药、阿莫西林等药，大家都较熟悉，许多家庭常备有此类抗生素药，碰上头疼发热或感冒咳嗽等小弊端，吃几粒似乎就能对付过去。抗生素不是万能药，切不可随意服用以至滥用，否则会贻误病情。 
　　抗生素滥用即不合理使用，主要表现为如下方面：一是不针对致病微有生命的物质，如用抗生素治感冒时，感冒大多是病毒传染，而不少抗生素是按捺球菌和某些微有生命的物质，不抗病毒；二是为防止或减少产生耐药性，在使用上抗生素分为一二三线药，三线药平时不用，在一二线药物无效时才使用，而患者往往不分一二三线，三线药也作一线药使用；三是不按医嘱服药，病情较重时定时按量服药，病情缓解时就少服或不服，达不到有效血药液体浓度，反而使球菌产生耐药性；四是多多益善，几种抗生素同时服用，引发大量耐药菌产生。滥用抗生素，会破坏体内的没事了菌群，使病菌耐药性增强而导致疾病无药可治，这在儿童中尤其严重，因为儿童在各个方面发育还不成熟，其对球菌、病毒以及对药物的耐受力相对成人来说是相当脆弱的，会导致很多问题，对他们未来的健康也埋下隐患。 
　　合理使用抗生素，关键是有的放矢。在用药上，能用窄谱抗生素，就不用广谱抗生素；能用低级抗生素，就不用高级抗生素。比如，炎症在临床上有红、肿、热、痛等表现，可分为过敏性炎症、坏死性炎症、球菌传染性炎症、病毒传染性炎症等。一位50岁的支气管气喘患者，本来是过敏性炎症，但由于滥用抗生素，导致体内菌群紊乱，引发肺部毛霉菌传染。后经医生对症治疗，让患者停用广谱抗生素，并有针对性地使用抗真菌药，患者很快痊愈。尽管合理使用抗生素也会产生耐药菌，但至少可以延缓耐药菌的发展速度。 
　　时下季候，常有感冒、嗓子疼、皮肤瘙痒等的侵染，按习惯，不少人会“跟着感觉走”，使用一些抗生素，认为可以消炎杀菌、控制病情，但结果往往不比想象中那么有效，有时甚或会加重病情。因此，在用药前应请医生诊断清楚后再用药，只有按医生处方规定的药量和时间距离严格用药才可使疾病在最短的时间内治愈。反之，想起来就用，想不起来就停，这样用用停停不但不能有效地杀灭体内的致病菌，而且还很容易使这些致病菌产生耐药性，给治疗带来更大的困难，延长恢复健康时间。 

　　抗生素分线： 
　　一线药：价格低价、副作用相对较小的常用药。如：青霉素，链霉素，红霉素，头孢氨苄，头孢拉定，氟哌酸，苦连素片，痢特灵等。 
　　二线药：用一线药三至五天后成效不抱负时选用的药。如：克林霉素，阿奇霉素，头孢呋肟，头孢克肟等。 
　　三线药：万古霉素等，多为打针剂，价格昂贵。 

　　一线用药：指对某种病治疗成效最好副作用最小的药物。 
　　青霉素类：青霉素G、苄星青霉素、奴佛卡因青霉素、青霉素V钾 、氨苄西林、阿莫西林、苯唑西林、氯唑西林、羧苄西林、哌拉西林、阿莫西林/克拉维酸、氨苄西林/舒巴坦 
　　头孢菌素：头孢氨苄、头孢唑啉、头孢拉定、头孢羟氨苄、头孢呋辛、头孢克罗、头孢丙烯 
　　氨基糖苷类：庆大霉素、阿米卡星、链霉素、妥布霉素 
　　氯霉素类：氯霉素 
　　大环内酯类：红霉素、琥乙红霉素、乙酰螺旋霉素、螺旋霉素、交沙霉素、麦迪霉素、白霉素 
　　四环素：强力霉素（多西环素） 
　　氟喹诺酮：诺氟沙星、氧氟沙星、环丙沙星、左氧氟沙星 
　　呋喃类：呋喃妥因、呋喃唑酮 
　　磺胺类：SD、SMZ/TMP、柳氮磺胺吡啶、磺胺脒 
　　其它类：甲硝唑、林可霉素、克林霉素、磷霉素、异烟肼、利福平、乙胺丁醇、吡嗪酰胺 
　　抗真菌药：制霉菌素、酮康唑 
　　抗病毒药：利巴韦林、阿昔洛韦 
　　中草药制剂：大蒜打针液、黄连素、板蓝根、双黄连、抗病毒口服液、香莲片、三金片、鱼腥草打针液 

　　二线用药（限制使用）：抗菌谱较广、疗效好，但不良反应较重或价格较贵的药物，或最近几年来耐药发展较为迅速的品种，属控制使用。管理措施：有药敏结果证实；若无， 应由高级职称医师检查打听签名；无高级职称医师的科室须由科室主任检查打听签名或有传染专科医生会诊记录 
　　青霉素类：美洛西林、阿洛西林、氟氯西林、阿莫西林 双氯西林、氨苄西林 氯唑西林、替卡西林/克拉维酸 
　　头孢菌素：头孢硫咪、头孢替安、头孢噻肟、头孢哌酮、头孢曲松、头孢地嗪、头孢唑肟、头孢甲肟、头孢米诺、头孢匹胺、头孢克肟、头孢布烯、头孢地尼、头孢特仑酯、头孢泊肟酯、头孢他美酯、头孢托仑酯 
　　其它β内酰胺：头孢西丁、头孢美唑、头孢替安、氨曲南、拉氧头孢、氟氧头孢 
　　氨基糖苷类：奈替米星、依替米星、异帕米星、大观霉素、卡那霉素、新霉素 
　　氯霉素类：甲砜霉素 
　　大环内酯类：乙酰吉他霉素、阿奇霉素、克拉霉素、罗红霉素、地红霉素 
　　四环素：四环素、美满霉素 
　　氟喹诺酮：依诺沙星、洛美沙星、培氟沙星、氟罗沙星、司帕沙星、莫西沙星、加替沙星、托苏沙星、芦氟沙星、那氟沙星、帕珠沙星 
　　糖肽类：去甲万古霉素 
　　其它类：替硝唑、多粘菌素B、对氨基蒲柳酸钠、利福喷丁、利福布丁 
　　抗真菌药：氟康唑、伊曲康唑、咪康唑、氟胞有机化合物 
　　抗病毒药：金刚烷胺、乙刚烷胺、泛昔洛韦、阿糖腺苷、干扰素、拉米夫定、阿昔洛韦 
　　
　　三线用药（特殊使用）：疗效独特但毒性较大、价格昂贵、新研制上市的抗菌药物以及一朝发生耐药即会产生严重后果的品种。管理措施：应由具有高级职称的科主任（或医疗小组组长）检查打听签名或传染专家会诊记录，或有全院疑难病例讨论意见，或报院“专家小组”核准。 
　　青霉素类：哌拉西林/三唑巴坦，及其它青霉素类/酶按捺剂复合物 
　　头孢菌素：头孢他定、头孢吡肟、头孢匹罗、头孢哌酮/舒巴坦，及其它头孢菌素/酶按捺剂复合物
　　碳青霉烯类：亚胺培南/西司他丁、美洛培南、帕尼培南/倍他米隆 
　　糖肽类：万古霉素、替考拉宁 
　　其它类：链阳霉素、恶唑烷酮、多粘菌素E 
　　抗真菌药：两性霉素B 

The most classic words about China's growth -- From my favorite Becker

Perhaps the most important problem, one not easily corrected because of strong political opposition, is that close to one half of manufacturing output is produced by state owned enterprises (SOEs). These enterprises are less efficient on the whole than private companies, they often have monopolies in their sectors, they are not important innovators, and they get privileged access to capital from state-owned banks.

The China 2030 report argues that the SOEs must operate more like commercial companies, but that is not easy since officials from the Communist Party usually have high positions in these enterprises, and many of the larger SOEs are closely related to the Communist Party and the military. The ideal solution would be to privatize most SOEs, but that does not seem likely in the near future. This is partly because government officials would lose power if SOEs were privatized, and partly because the government fears that privatized companies would greatly cut employment and increase social unrest.Unfortunately for China, it would not be possible to close rapidly the per capita income gap with rich countries as long as a large fraction of manufacturing output in China is produced in over-manned and inefficient state enterprises.

Private companies in China have great difficulty borrowing from state banks since most of their lending goes on favorable terms to the SOEs. The financial crisis in the West has increased the reluctance of Chinese leaders to open their capital markets to competition from foreign banks and funds. Yet greater private banking access to Chinese companies and households seems essential for China's continued rapid growth.

China is very worried about social unrest, as it observes the Arab Spring and other unrest toppling governments. Many protests in China originate in rural areas where farmers complain about their inability to sell the land they farm, and about local governments that arbitrarily take their land to build factories or infrastructure. The Chinese government also fears the 150 million migrant workers who complain about their low wages, and about the discrimination against them in gaining access to housing, schools for their children, and health services. Unrest also arises from non-migrant factory workers who complain about working conditions, and arbitrary differences in wages between workers with similar productivities. Basically, most of the unrest in China is due to the fact that much of the increase in inequality is not grounded in productivity differences, but rather in discriminatory government rules and behavior.

As China continues to grow, households will demand that a larger fraction of national income goes into consumer goods and services at the expense of investments and the accumulation of foreign reserves. Spending on consumer goods accounts for only 35% of China's GDP compared to over 70% in the US. Chinese enterprises would be induced to look more to its domestic market if the Renminbi was allowed to float and appreciated a lot relative to the dollar and other currencies. For then Chinese companies would have more trouble exporting their outputs to other countries.

Ultimately, the challenge for China is to move more toward a private enterprise economy with flexible and competitive labor and capital markets, where assets like land can be bought and sold rather freely, and where workers are free to move around the country without discrimination, and to take whatever jobs they want. I confess I do not know if China will make these reforms quickly enough to prevent a sizable slowdown in their drive to becoming a rich country. The experiences of both the Soviet Union and Japan shows both that it is very hard for countries to change their ways when they have had considerable economic success, and that the slowdown in growth rates is abrupt once it happens. Still, I would not bet against the ability of Chinese leaders to radically change their economic ways once again if that becomes necessary to continue to grow rapidly.

Source: Is China's Economic Future a Rosy One? 

凹函数

       如果函数f(x)在区间I上二阶可导，则f(x)在区间I上是凹函数的充要条件是f''(x)>=0;f(x)在区间I上是凸函数的充要条件是f''(x)<=0;

　　不过补充一下，中国数学界关于函数凹凸性定义和国外很多定义是反的。Convex Function在国内的数学书中指凹函数。Concave Function指凸函数。在国内涉及经济学的很多书中，凹凸性的提法和国外的提法是一致的，也就是和单纯的数学教材是反的。很头大的问题。

　　另外，国内各不同学科教材、辅导书的关于凹凸的说法也是相反的。一般来说，可按如下方法准确说明：

　　1、f(λx1+(1-λ)x2)<=λf(x1)+(1-λ)f(x2) ， 即V型，为"凸向原点"，或"下凸"（也可说上凹），（有的简称凸有的简称凹）

　　2、f(λx1+(1-λ)x2)>=λf(x1)+(1-λ)f(x2) ， 即A型，为"凹向原点"，或"上凸"（下凹），（同样有的简称凹有的简称凸）

　　凸/凹向原点这种说法一目了然。上下凸的说法也没有歧义