# st: collinearity/non-convergence problem with -asclogit- command

 From Cielo Magno To statalist@hsphsun2.harvard.edu Subject st: collinearity/non-convergence problem with -asclogit- command Date Mon, 12 Oct 2009 20:08:35 -0400

```Hello everyone,

I am hoping someone will be able to help me with my problem. I am new
with Stata and I am trying to run the -asclogit- command. The model
always results in non convergence because of collinear variables.

variable and 1 case-specific variable but I can’t even get pass it.
This is the command I am using:

. asclogit choice price2, casevars(age) case (id) alternative (alter) iter(5)

This is how my data looks like.  There are 11 products, my
alternative-specific variables are the price of the product and the
amount of money they spent on advertising every month.

I tried to replace price2 with the advertising variable and the result
is still the same.  I also tried creating a dichotomous variable (by
transforming my advertising variable into a dichotomous yes/no
variable) and using it as the alternative-specific variable but the
result is the same – non convergence.

+-----------------------------------------------------+
| choice   	price2   age   id    	alter   	total_ads |
|-----------------------------------------------------|
1. |      1      	110	83   33      	product1    15488033 |
2. |      0       	92  	83   33      	product2    11891267 |
3. |      0	                101	83   33    	product3    0 |
4. |      0       	77    	83   33      	product4    0 |
5. |      0       	82    	83   33   	product5  	49783.33 |
6. |      0      	104    	83   33       product6   	27916.67 |
7. |      0      	122    	83   33   	product7    21012.50 |
8. |      0      	168    	83   33    	product8   166.67 |
9. |      0 	                 107    	83   33     	product9    0 |
10. |     0       	 58    	83   33   	product10  0 |
11. |     0      	153    	83   33      	product11  0 |
|-----------------------------------------------------|
12. |      1      	110 	61   37   	product1    15488033 |
13. |      0       	92    	61   37      	product2    11891267 |
14. |      0      	101    	61   37    	product3    0 |
15. |      0       	77    	61   37       product4    0 |
16. |      0       	82    	61   37   	product5   	49783.33 |
17. |      0      	104    	61   37       product6   27916.67 |
18. |      0      	122    	61   37   	product7    21012.5 |
19. |      0      	168    	61   37    	product8   166.67 |
20. |      0      	107    	61   37     	product9    0 |
21. |      0       	58    	61   37   	product10  0 |
22. |      0      	153    	61   37      	product11  0 |
+-----------------------------------------------------+

I can’t figure out/find a solution to my problem.  I am using Stata/IC
11.0 and it is updated.  Any help will be greatly appreciated.
Thank you very much.

Cielo Magno