First some light reading.
http://io9.com/5975778/scientific-evidence-that-you-probably-dont-have-free-will?trending_test_b&utm_expid=66866090-62.H_y_0o51QhmMY_tue7bevQ.2&utm_referrer=https://www.google.com/
http://forums.philosophyforums.com/...ot-an-argument-against-determinism-35884.html
The answer to your question is in one way, disappointing much like the answer given by Stephen Hawking to whether or not time travel is possible. Let's break it down:
1. The chain of events method. This method relies on the perfect observation of material objects. It starts at the outcome, and traces backward it's journey through the cosmos to the point of the first cause, the big bang.
2. The first article looks at free will from a neurological viewpoint. In determining that the brain makes decisions sometimes well in advance of one being conscious of said decision one can say that by design the brain precludes the possibility of true free will.
3. What does this mean, socially? Absolutely nothing. Just because the mechanism by which we make decisions is neither truly independent, nor are we able to break free of the chain reaction started by the big bang, (even at the quantum level), does not give us license to break socially agreed upon rules. This is largely in part due to the fact that we DO experience a sense of choice even if it's an illusion. Since we feel this sense of choices we ought act upon the assumption that we have these choices to make.