Recent content by noetsi

  1. noetsi

    Linear Probability Model

    This is when you use linear assumptions for a DV that has two levels only. SAS's senior statistician told me firmly this only works when you assume a binomial distribution. However, the organization I report to chose to assume normality. As I understand it, this is not then a Linear Probability...
  2. noetsi

    Control variables

    I run a time consuming report for a bunch of variables the federal government controls for. My argument is that it does not matter what their levels are, because the federal government will control for them in evaluating our success (that is their purpose to level the playing field). But then I...
  3. noetsi

    MCAR, MAR, MNAR test

    I have seen missing modeled with a dummy variable 1 when missing, but not what you suggest. Thanks.
  4. noetsi

    Interpreting dummy variables.

    I am, rather the federal government is its not my choice, using a model that assumes normality to predict a two level dependent variable coded 1 and 0. They are not generating a log odds, and since they are not assuming a binomial distribution they are not even running a linear probability model...
  5. noetsi

    MCAR, MAR, MNAR test

    I am not sure what you mean by examine with modeling.
  6. noetsi

    MCAR, MAR, MNAR test

    I read an article today that stressed the need when data is missing more than two percent of cases to test whether it is MCAR MAR, MNAR. Does anyone know how to do such a test. I understand MAR is tied to being associated with the predictors and the MNAR with Y. But not how to do a formal test...
  7. noetsi

    Importance of regression assumptions

    Long ago I was brought up on the view that analysis of the residuals was critical for regression. But I am confused about the advice on it now. This is for data sets that has thousands (or tens of thousands of points) . That is how important is residual analysis? Normality: The sense I get is...
  8. noetsi

    Probability of dying from Covid today

    From what I have read the rate of serious injury is very small if vaccinated. No one knows the dangers from the vaccines, but there is little evidence it is large. There are likely few medicines that hurt absolutely no one. COVID has primary and secondary effects. When a lot of people get sick...
  9. noetsi

    Running simulations in R

    My concern with that is many simulation studies set a series of limits on the data, for example it has to be in a specific range, not just there be a specific distribution. But as I go through the R code it probably allows you to do that. When I find an example of what I mean I will post it.
  10. noetsi

    Running simulations in R

    They are way beyond my expertise, interest, or intelligence. :) I am trying to do basic simulation. Say I think there is an issue with a method (or more likely others do). Then I could test the various arguments with a simulation. That is what I would like to be able to do.
  11. noetsi

    Running simulations in R

    You need Proc IML to do it in SAS. I have an awesome book for that. But I will never have Proc iml
  12. noetsi

    Running simulations in R

    Do you mean there are functions that tell the base r to simulate data given certain assumptions?
  13. noetsi

    Running simulations in R

    I have wanted to do this for a long time. But the package that does this in SAS (PROC IML) is too expensive. I was wondering, and remembering that I am a beginner in both R and simulations, what a good R package would be to do this.
  14. noetsi

    proc genmod binary DV linear probability model

    I missed where it does that. I will have to go back and read it again. This is an interesting article hlsmith. Some big names here (one of whom is a big LPM) fan. Microsoft PowerPoint - Better Predicted Probabilities.pptx (stata.com) in SAS is this the correct way to specify a LPM? PROC...
  15. noetsi

    proc genmod binary DV linear probability model

    Do you mean the probabilities are not near 0 or 1 on average? Its the wrong model even then, the SE are messed up and the relationship is inherently non-linear - but the model won't show you that.