雅虎香港 搜尋

搜尋結果

1. 機票搜尋

   • 來回
   • 單程
   • HKG
   • 立即搜尋

   Powered by

2. zhuanlan.zhihu.com › p › 637966068知乎专栏 - 随心写作，自由表达 - 知乎簡

   zhuanlan.zhihu.com › p › 637966068

   知乎专栏提供一个自由写作和表达的平台。

3. zhuanlan.zhihu.com › p › 120000152知乎专栏 - 随心写作，自由表达 - 知乎簡

   zhuanlan.zhihu.com › p › 120000152

   • 概览
   • 一
   • 二

   这次的帖子，我们用 QJE的PROXIMITY AND INVESTMENT: EVIDENCE FROM PLANT-LEVEL DATA 这篇论文来拆一下论文中的data与specification的写作部分。

   Giroud, X. (2013). Proximity and investment: Evidence from plant-level data.The Quarterly Journal of Economics,128(2), 861-915.

   在「zhuanlan.zhihu.com」查看更多資訊

   根据Scientific Research Writing for Non-native Speakers of English里面将methodology部分分为四个模块：

   1.Provide a general introduction and overview of the materials/methods

   •Restate the purpose of the work

   •Give the source of materials/equipment used

   •Supply essential background information

   2. Provide specific and precise details about materials and methods

   在「zhuanlan.zhihu.com」查看更多資訊

   实际上在经济学论文中，这部分的差异和自然科学还是比较明显的，方法部分可以明确的分为三个部分：数据，模型与变量的定义或测度，有时候后两个会合并在一起，有时候第一个和第三个合并在一起。例如在本文中，就分为三个部分：Data Sources and Sample Selection，Empirical Methodology，Defination of Variables。接下来我们分开看下这篇论文怎么写的。

   A.Data Sources and Sample Selection

   Plant-Level Data. The data on manufacturing plants are obtained from three different data sets provided by the U.S. Census Bureau. The first data set is the Census of Manufactures (CMF). The CMF covers all U.S. manufacturing plants with at least one paid employee. The CMF is conducted every five years in years ending with 2 and 7 (‘‘Census years’’). The second data set is the Annual Survey of Manufactures (ASM). The ASM is conducted in all non-Census years and covers a subset of the plants covered by the CMF: plants with more than 250 employees are included in every ASM year, whereas plants with fewer employees are randomly selected every five years, where the probability of being selected is higher for larger plants. Although the ASM is referred to as a ‘‘survey,’’ reporting is mandatory, and fines are levied for misreporting. The CMF and ASM cover approximately 350,000 and 50,000 plants per year, respectively, and contain information about key plant variables, such as capital expenditures, total assets, value of shipments, material inputs, employment, industry sector, and location. The third data set is the Longitudinal Business Database (LBD), which is compiled from the Business Register. The LBD is available annually and covers all U.S. business establishments with at least one paid employee. The LBD contains longitudinal establishment identifiers along with data on employment, payroll, industry sector, location, and corporate affiliation. I use the longitudinal establishment identifiers to construct longitudinal linkages between the CMF and ASM

   上面这一段是关于数据来源的细节问题，可以看到主要是三类内容，数据来源（obtained from, compiled from），数据生成过程(conducted)与覆盖范围(covers)，数据包含的信息(contain)。所以接下来就要讲对这三个数据的操作，在在操作部分就会有更多讲到为什么要这么做。

   Given that the LBD covers the entire U.S. economy, it also contains information about non-manufacturing establishments of companies that have plants in either the CMF or the ASM. I use this information to construct firm-level variables, such as the total number of employees and the number of establishments per firm. For my analysis, the most important firm-level variable is the ZIP code of the company’s headquarters. 这句属于论述了。At the firm level, the Census Bureau distinguishes between single- and multi-unit firms. Single-unit firms consist of a single establishment, which means headquarters and the plant are located in the same unit. Multi-unit firms consist of two or more LBD establishments, with one establishment being the company’s headquarters. 解释headquater的细节

   To determine the location of headquarters, I supplement the LBD with data from two other data sets provided by the Census Bureau: the Auxiliary Establishment Survey (AES) and the Standard Statistical Establishment List (SSEL). The AES contains information on non-production (‘‘auxiliary’’) establishments, including information on headquarters. The SSEL contains the names and addresses of all U.S. business establishments. Appendix A outlines the procedure used to obtain the location of headquarters from these data sets. The main source of information about headquarters, the AES, is available every five years between 1977 and 2002. To fill in the missing years, I use the information from the latest available AES. Given that the Census years are deterministic, this measurement error is unlikely to introduce any bias. It merely introduces noise into the regression, which makes it harder for me to find any significant results. 最后两句话的作用Indicate what appropriate care was taken

   在「zhuanlan.zhihu.com」查看更多資訊