<p><br/></p><p>课上的作业。没有基础，于是一片茫然。</p><p>附件里面是.dta文件和作业要求</p><p>我对这个没想法了。</p><p>d) Predict conditional probability for single outcome within group accord-<br/>ing to the third speci&macr;cation. Within group the choice variable which<br/>has the largest predicted probability is the predicted outcome. Tabulate<br/>predicted choice outcomes and report percentage of correct predictions<br/>for each outcome.</p><p></p><p>还有，请仗义的XDJM帮我看看，我前面想的对不对</p><p></p><p>use D:\TRAVEL</p><p><br/>a)Descriptive statistics. 3 P<br/>&sup2; Report the proportion of choices.<br/>&sup2; Report the descriptive statistics of individual specific variables.<br/>&sup2; Report the descriptive statistics of the alternative-specific variables<br/>by the choice outcome.<br/>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>proportion air train bus car<br/>summarize choice mode costs transt hinc pers air train bus car<br/>sort choice<br/>by choice:summarize mode costs transt hinc pers</p><p>b)Estimate three di&reg;erent conditional logit specifications.<br/>&sup2; Use for the first specification only attribute specific information.<br/>&sup2; Let the second specification additionally contain attribute specific<br/>intercept terms.<br/>&sup2; The third specification should contain attribute specific and indi-<br/>vidual specific variables.<br/>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>logit choice mode costs transt hinc pers, group(id)<br/>[这里非常非常茫然T___T]</p><p><br/>c) Display odds ratio using relevant command in STATA. Interpret the<br/>coe±cients of the most general specification. What do the estimated<br/>coe±cients tell us about the e&reg;ect of the corresponding X variable on<br/>the choice probabilities?<br/>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</p><p>logistic air transt</p><p>[在网上查的关于odds ratio的意义和做法，<a href="http://www.ats.ucla.edu/stat/Stata/library/odds_ratio_logistic.htm">http://www.ats.ucla.edu/stat/Stata/library/odds_ratio_logistic.htm</a><br/>更复杂的就不清楚了]</p><p><br/>帮帮我吧……</p>