i have a multilevel model at firm and local authority district level, with both firm level and LAD level predictors. It is a binary logistic model, the outcome is presence of women on the board of a firm (true/false). I scaled any variables that aren't percentages. Lots are binary -could this be a problem? My single level logit regression worked well.
multilevel_model1 <- glmer(at_least_1 ~ log_board_size + log_employees + scaled_company_age + self_employed + scaled_average_age +
industry + tech_employment + log_population_density + scaled_gpg +
level4_qual_f + economic_activity_f + private_sector_f +ft_median_pay_f +
(1 | ladcd.x),
data = multi_level_data,
family = binomial(link = "logit"),
control = glmerControl(optCtrl = list(maxfun = 10000)))
summary(multilevel_model1)
I tried changing the optimizer to bobyqua (?) but it didn't help. i get this error:
Model failed to converge with max|grad| = 0.207839 (tol = 0.002, component 1) Model is nearly unidentifiable: very large eigenvalue
- Rescale variables? Model is nearly unidentifiable: large eigenvalue ratio
- Rescale variables?