Not necessarily. Here is the best answer I have found about this question myself:
This is a good question, and it requires layers of knowledge, sort of like an onion. You keep peeling them back.
If I discover your site today and only visit once in the morning and once in the afternoon (from the same computer and same browser) I am one unique visitor. But I had two visits. The first time that I visited, I had a New Visit, because I had never visited before. The second time that I visited (that afternoon), I had a repeat visit (becuase I had visited before.) So in this example, we have two visits. We also had only one Absolute Unique Visitor and one New visit.
Now, let's say that I discover your site on Monday, January 5, 2009, and visit every weekday that week (once a day, always from the same computer, always from the same browser.) If I set my calendar to include the full week, GA sees five visits, one new visit, and one Absolute Unique Visitor. ( The good part is coming.)
However, the web analyst could set his calendar to worry about only Wednesday, January 7 and Thursday, January 8. For those two days, we will see: two visits (one each day, right?), one unique visitor and NO new visits.
Why not? Remember that I discovered the website on Monday. When I visited on Monday, I was new. GA puts a cookie on my browser at that point, and everytime I come back, I am considered a returning visitor.
So the dates that you choose to measure greatly affect the results you get, and the difference between absolute unique visitors and new visits. Of to put it another way: Absolute Unique visitors and New Visits are always the same if your calendar is set to always include every single new visit. As soon as you screen out some of the new visits, by having only a month instead of all time in your calendar, you will lose some of the new visits, but some of those people will come back during the time period you are measuring, they will be unique to the period but not new.