Missing values?
Hello. I have experimental data, imported to Stata from Qualtrics. So for the variable, group 1 (control group), and other two groups: group 2 and group 3, the value for respondents is "1" if in one of...
View ArticleFixed-Effects: Dropping those already in the treatment group without having...
I learned that when conducting a fixed-effects analysis one should exclude everybody who is already in the treatment group in wave 1, because one cannot examine the before-and-after-effect in this...
View ArticleAutoregressive Least Squares (ALS) - Cochrane - Orcutt Regression
I will Introduce here some examples for Autoregressive Least Squares (ALS) models and especially Cochrane - Orcutt Regression via: 1- ALS - Autoregressive Least Squares transformations. 2- NLS -...
View ArticleTable of means
Hi statalisers, I am trying to convert this type of twoway frequencies table: tab Y Time | Time Var Y | 1 2 3 4 5 | Total -----------+-------------------------------------------------------+----------...
View ArticleQuestion about the results in piecewise poisson regression
Hi all, Code: poisson income c.iv1##c.iv2 c.iv1#c.iv1 c.iv2#c.iv2 cv1 cv2 cv3 cv4 i.indcode i.areacode, vce(robust) Array Then, I drop one of c.iv1#c.iv1, and it becomes significant. Code: poisson...
View Article3 level random intercept model with xtmixed: standard errors calculation failed
I am using xtmixed in Stata 12 to estimate a random intercept model. I have overtime observations (8 years) for 250 regions which are nested in 28 countries. The estimates for the standard errors at...
View ArticleConflicting advice on specifying post stratification weights in svyset
Hi, I have tried sorting this one out by looking at previous fora, the manual and the YouTube video but actually feel i have got conflicting advice. I am trying to correct for different distributions...
View ArticleGroup sequential design for safety monitoring - Whitehead's Triangular test
Hi, I need to use Whitehead's Triangular Test (http://www.ncbi.nlm.nih.gov/pubmed/11042622) for a group sequential design monitoring safety in a trial (so a one-sided test). I cannot find anything that...
View ArticleTwo-way cluster with cluster2 and country specific time trend
Hi, I have a question related to using the cluster2.ado and also including a country specific year trend. I am trying to use the cluster2 program for double clustering of standard errors and also would...
View ArticleWhat is the difference between these two robust standard error?
What is the difference between ,vce(r) and ,r ?
View ArticleHow to create a variable as total cases for patient who has comorbitidy
Dear all, I have a problem with my dataset which contains number of cases of some diseases. However, each patient may have comorbidity. For instance, the one can get 2,3 or more diseases...
View ArticleHow to use coefficients from a previous regression in another regression?
Hello, I regressed my 10 dependent variables on 10 different variables (cross-sectional regression) getting 10 betas (one for each regression). Then I used estout to save my coefficients. But now I...
View ArticleGenerating a new variable sorted by date
I want to generate a new variable. I have a dataset where I have two observations for implied volatility for each day, for every firm. Now I want to take the average of these two values, sorted by firm...
View ArticleHow to interpret the coefficent of a control variable in the log form in...
Hi all, Code: poisson income c.iv1##c.iv2 c.iv2#c.iv2 cv1 cv2 cv3 cv4 i.indcode i.areacode, vce(robust) I want to know how to interpret the coefficent of a control variable in the log form in poisson...
View ArticleAsk: Profit maximization using forvalues/foreach
Hi, I am writing commands to find the optimal values for maximum profit, though encountering some errors. Basically, have those variables: p_i: loss probability of individual - exogenous, [0,1] L_i:...
View ArticleBar graph bar width
Hey! I'm creating a simple bar graph and I have difficulties to change the width of the bars. When I try 'barwidth', then I get the error that this option is not allowed. I tried with the following...
View ArticleEncode/ Destring a dataset
Dear All, I need to transform a 'string' dataset by taking logs. While 'destringing' would be most appropriate, it generates no observations however 'encoding' does. I proceeded to take logs, however...
View ArticleXlabel Bar Graph
Why can I not change the xlabels of by bar graph from numbers to meaningful names? I get always the following error messages: xlabels(1 PGM" 0 "PGM invalid name r(198); Code: #delimit ; graph bar...
View ArticleSeemingly unrelated regression using gsem - data in long format
I want to do a seemingly unrelated regression using nbreg as my family, since I have a long, narrow panel of count data that are overdispersed. My research indicates that I should use the gsem...
View ArticleMIMIC modelling - Interpretation of interaction effect
Hi everyone, I'm planning on running a Multiple Cause Multiple Indicator (MIMIC) model in STATA. Although I am familiar with the main command, I also plan to look for an interaction effect of two...
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