# Stata-->R

Stata 官网刚刚 po 出了 Dr. Tim Essam 和 Dr. Laura Hughes 合作编写的 Stata 速查。包括数据处理、数据分析、数据转换、编程、可视化等内容，应该是最新最全的了（官网链接 https://www.stata.com/bookstore/stata-cheat-sheets/ ）。

# How to Write the Introduction [by David Evans]

Various economists have provided advice on how to write an introduction. Keith Head gives “The Introduction Formula”: (1) the hook: attract the reader’s interest, (2) the question: what your paper does, (3) antecedents: what work you build on, (4) value-added: how you add to the work you build on, and (5) roadmap of the paper.

Claudia Sahm provides related advice: (1) motivation, (2) research question, (3) main contribution, (4) method, (5) findings, (6) robustness check, and (7) roadmap of the paper.

How does this play out practically? I identified the most recent empirical microeconomic development papers from a range of top journals, including the American Economic Review (AER), the Quarterly Journal of Economics (QJE), American Economic Journal: Applied Economics (AEJ: Applied), and others. Then I outlined the introduction of each paper: What do the authors do in paragraph one? What about paragraph two?

Here’s what I learned.

# 文献阅读: Agricultural Productivity and Structural Transformation

农业生产率与结构转型：来自巴西的证据

Date: 26-03-2018

# Words differences(ongoing)

In particular“ is an idiomatic expression that means “in distinction from others” or “specifically”. This expression usually refers to nouns and is set apart by a comma when it occurs at the beginning of a sentence or a phrase.
Particularly“ means “in detail” or “to an unusual degree”. It is an adverb, and as such it can be used to modify a verb, an adjective, or another adverb but not nouns. It is not set off by a comma from the rest of the sentence.

# Log transform with O

Variables log-transform is a common method to obtain the elasticities or a requirement such as estimating a Cobb-Douglas or translog form production function. However, when we encounter the zero-valued observation, what should we do? Because log(0) is undefined.