Hi all,

When I use the i.command to run the regression as follows:

Code:
 reg coverage i.year i.planning i.finance i.performance,r
The results show as:
coverage Coef. St.Err. t-value p-value [95% Conf Interval] Sig
Planning
1 planning Baseline
2 planning -1.088 .545 -2.00 .046 -2.158 -.018 **
3 planning 1.815 .568 3.19 .001 .7 2.93 ***
4 planning 1.277 .617 2.07 .039 .067 2.488 **
Finance
1 finance Baseline
2 finance -2.253 .48 -4.69 .000 -3.195 -1.31 ***
3 finance -2.326 .515 -4.52 .000 -3.335 -1.316 ***
4 finance Omitted
Performance
1 performance Baseline
2 performance -3.117 .517 -6.03 .000 -4.131 -2.103 ***
3 performance -1.68 .48 -3.50 .000 -2.623 -.738 ***
*** p<.01, ** p<.05, * p<.1
Here, 1.2.3.4 is different levels of three assurance indicators (finance, performance and planning). The y variable is the coverage rate of the vaccine. I omitted level 1 as the baseline.

I am confused about why Finance 4 is omitted. My explanation is because of a high similarity or correlation of coverage between level 1 and level 4.

I try the matrix diagram: and I still cannot infer the clues or reasonings behind this collinearity.

I try the line of mean coverage by 4 levels of Finance, and it seems that the trend of level 1 and level 4 are very common. Can this support the collinearity of Finance 4?

Thanks in advance, and really looking forward to your ideas!

Matrix diagram and line diagram are attached in attachments. Array
Array