Arresting for misdemeanors?

I have a question that probably relates to many areas of California but I am speaking about Shasta County in particular.

We arrest 4600 per 100,00 residents VS county average of 2500 per 100,00.

Our felony arrests are 18% VS county average of 29%.

Our misdemeanor arrests are extremely high. My question is why would this be? Is this a mandate by superior officers who are being mandated by uppers yet again?

Arrests are expensive all the way around and I would feel this impacts our county budget, DA budget and ultimately pulls officers from more serious police work.

Thoughts please from a concerned citizen.