Beginner-question!

[eimelb]

I'm doing my research project for my 'Introduction to Econometrics' module. It's on finding the determining factors of traffic accidents in California, and I've been supplied with a dataset (time-series) I need to use. There are very many dependent variables I can use, so to keep things as simple as possible I've chosen to use Total Accidents (statewide) for my main model. No confusion just yet. In addition to this, I thought I would would include one more model using Fatal Accidents as the dependent variable as my time period stretches from 1981 to 1989, a period that saw the introduction of the seat belt law and the 10 mph increase in the National Maximum Speed Limit – both policies that were the subjects of intense public debate regarding the impact (or lack thereof) on traffic casualties.

Obviously the Fatal Accidents is a part of Total Accidents, and I was just wondering if this posed issues of any kind?

(I am planning to use a semi-log lnY functional form for both equations)