Hello!   I'm having a few problems trying to get effects for a three-way interaction in the "Predictive margins and average marginal effects" (%margins) macro on SAS 9.4 using Windows 10: https://support.sas.com/kb/63/038.html   Right now, I'm attempting to run a model focusing on four variables of interest (1 DV, 3 variables involved in a 3-way interaction), with the goal of examining effects of t7dmar_c on Mar_8 at different levels of both t7c_can_neg AND t7c_at_EC Mar_8 is the outcome variable and has a negative binomial distribution Mar_7 is a continuous predictor variable t7dmar_c is a continuous predictor variable involved in 3-way interaction t7c_can_neg is a continuous predictor variable involved in 3-way interaction t7c_at_EC is a continuous predictor variable involved in 3-way interaction All other variables are simply covariates held at their means    Here is my sas code for the macro: libname ques "Enter your location"; run; %inc "your location\margins.txt"; /*TESTING 3 WAY IXN*/ options mlogic mprint symbolgen; %Margins(data = ques.atmeansdata, class = t7cgender t7marorder_c, response = MAR_8, dist = negbin, model = t7cgender t7cnuage t7dmar_c t7marorder_c t7C_can_neg t7c_can_pos t7C_AT_EC MAR_7 t7dmar_c*t7C_can_neg t7C_AT_EC*t7C_can_neg t7dmar_c*t7C_AT_EC t7dmar_c*t7C_AT_EC*t7C_can_neg, effect = t7dmar_c, at = t7C_can_neg t7C_AT_EC, atwhere = t7c_can_neg in (3.3333333333, 3.2962962963, 2.33333, 1.00000) and t7c_at_ec in (5.5263157895, 3.7368421053, 3.6842105263, 2), options = cl atmeans); Unfortunately I keep getting two errors (see log attached).   1. One states that "The ID value "b_t7dmar_c_t7C_can_neg" occurs twice in the input data set." I suspected that this might have to do with the 3-way interaction in the model (as this has not occurred in two-way interaction models). After removing the 3-way interaction term, the error goes away. This leads me to the question: Should I include interaction terms in the model statement? From what I can tell, including the interaction terms DOES affect the effects of Mar_7 on Mar_8, so it concerns me that the model won't run with the 3-way interaction term. Any information and thoughts on this would be helpful.   2. Another error states that "A character operand was found in the %EVAL function or %IF condition where a numeric operand is required. The condition was: &nfix=0". I've used this macro with two "atmeans = " variables and not had this happen. As far as I can tell the syntax for the locations of the effects is correct. The locations of the "atmeans = " variables are very specific, as I'm looking for effects of Mar_7 at approximately 10th and 90th percentiles of both variables. I located levels of these variables where there are values present in the data (i.e., someone in the data endorsed a specific combination of these levels of these variables), so the problem doesn't appear to be that there is no data for which to compute an effect at these combinations. Why might I be getting this error for this model?   Log and sample data are attached.   Thank you!     ... View more

Hello!   I'm having a few problems trying to run and interpret output from the "Predictive margins and average marginal effects" macro on SAS 9.4 using Windows 10: https://support.sas.com/kb/63/038.html   Right now, I'm attempting to run a simplified model using four variables, with the goal of examining margins effects of t7dmar_c on Mar_8 at different levels of t7cgender (i.e., the interactive effect of t7cgender*t7dmar_c): Mar_8 is the outcome variable and has a negative binomial distribution Mar_7 is a continuous predictor variable t7dmar_c is a continuous predictor variable t7cgender is a dichotomous (0, 1) predictor variable, to be examined as a moderator of the relationship between t7dmar_c and Mar_8   Here is my sas code for the macro:   %Margins(data = marginsdata, class = t7cgender, response = MAR_8, dist = negbin, model = t7cgender t7dmar_c MAR_7 t7dmar_c*t7cgender, margins = t7dmar_c, at = t7cgender)   I've gotten the macro to run in this form; however, I'm having trouble with a couple of things:   1. The output for the regression provides coefficients for t7dmar_c in the order of ~0.4, but the marginal effects provides coefficients ranging from ~40-100. Why would this be? My understanding is that these marginal effects should be using the sample units as in the regression. See attached for an XL file containing the output, as well as data.     2. The macro takes a VERY LONG time to run on my computer (several hours, to overnight, depending on the type of model I'm running). This is especially true when using a continuous variable in the "at = " portion. In some cases I even get "ERROR: The SAS System stopped processing this step because of insufficient memory." I'm guessing this is because it is estimating an enormous number of effects, especially in the case of the interaction between two continuous variables. I don't need marginal effects at every level in the data, and believe reducing the number of levels at which these effects are estimated should solve this problem (e.g., as it has above using a dichotomous moderator). I've read in the notes that I could request specific levels of marginal effects using both the "marginswhere = " and "atwhere = " statements. Yet, I cannot figure out how to get the model to produce marginal effects at only these levels.    For example:      %Margins(data = marginsdata, class = t7cgender, response = MAR_8, dist = negbin, model = t7cgender t7dmar_c MAR_7 t7dmar_c*t7cgender, margins = t7dmar_c, marginswhere = 1, at = t7cgender)     This will run, but provides no different output than the previous model. I would expect it to provide marginal effects of t7dmar_c only at 1. How can I request specific levels of the marginal effects? Any examples would be appreciated, as none are provided in the "Results" portion of the macro description. Perhaps I'm not understanding how these statements should be used, but I could use some help figuring it out.    Thank you! ... View more