翻訳と辞書 Words near each other ・ Differential heat treatment ・ Differential ideal ・ Differential inclusion ・ Differential inheritance ・ Differential interference contrast microscopy ・ Differential invariant ・ Differential item functioning ・ Differential Manchester encoding ・ Difference and Repetition ・ Difference density map ・ Difference due to memory ・ Difference engine ・ Difference feminism ・ Difference gel electrophoresis ・ Difference hierarchy ・ Difference in differences ・ Difference in the depth of modulation ・ Difference list ・ Difference of Gaussians ・ Difference of Opinion ・ Difference of two squares ・ Difference polynomials ・ Difference quotient ・ Difference set ・ Difference theory ・ Difference United ・ Difference-map algorithm ・ Differences (journal) ・ Differences (song) ・ Differences between Sunni, Shia and Ibadi Islam Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Difference in differences ： ウィキペディア英語版 Difference in differences Difference in differences (sometimes 'Difference-in-Differences', 'DID', or 'DD') is a statistical technique used in econometrics and quantitative sociology, which attempts to mimic an experimental research design using observational study data. It calculates the effect of a treatment (i.e., an explanatory variable or an independent variable) on an outcome (i.e., a response variable or dependent variable) by comparing the average change over time in the outcome variable for the treatment group to the average change over time for the control group. This method may be subject to certain biases (mean reversion bias, etc.), although it is intended to eliminate some of the effect of selection bias. In contrast to a within-subjects estimate of the treatment effect (which measures differences over time) or a between-subjects estimate of the treatment effect (which measures the difference between the treatment and control groups), the DID measures the difference in the differences between the treatment and control group over time. ==General definition== Difference in differences requires data measured at two or more different time periods. In the example pictured, the treatment group is represented by the line P and the control group is represented by the line S. Both groups are measured on the outcome (dependent) variable at Time 1 before either group has received the treatment (i.e., the independent or explanatory variable), represented by the points P1 and S1. The treatment group then receives or experiences the treatment and both groups are again measured after this at Time 2. Not all of the difference between the treatment and control groups at Time 2 (that is, the difference between P2 and S2) can be explained as being an effect of the treatment, because the treatment group and control group did not start out at the same point at Time 1. DID therefore calculates the "normal" difference in the outcome variable between the two groups (the difference that would still exist if neither group experienced the treatment), represented by the dotted line Q. (Notice that the slope from P1 to Q is the same as the slope from S1 to S2.) The treatment effect is the difference between the observed outcome and the "normal" outcome (the difference between P2 and Q). 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Difference in differences」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.