Just recently my two year old lab has started to run away from me when we are somewhere new or he sees someone walking by or he has done something in the house he was not supposed to and I have to chase him. For example, I took him to a secluded place to throw the ball as I still do not quite trust him to not just take off. He did great for a few throws but then decided he wanted to explore. He did not respond to my come command or no. I had to chase him which is not good. My last lab was extremely well behaved and I did not experience this.
Any ideas on how I can break this dangerous and annoying habit?
Yes, do not let him off leash. He is not reliable and by doing so, you could be endangering him.
Also, it's important to never call them to you to punish them.
I would go back to the basics and start working on "come". Put him on a long line and reel him in when you say "come". Personally I taught it like this -- every single time my girl comes to me she is rewarded w/ a treat. Why? Because I think it's the most important command there is (and she is a highly food motivated dog). Wherever we are -- in the house, in the yard, in the woods -- when I say come, she does, and she is rewarded. The downside is that I have to walk around w/ treats. The upside is it has worked like a charm.
I'm sure you'll get alot of different opinions, so I'll just say it has worked for me.
I teach the recall in a similar way to ThatsMyGirl.
For starters, my pups were never off the leash unless we were training. Being off leash is NOT a right, its a privilege, and I have a "you abuse it, you loose it" attitude. I think this attitude is especially important as the recall is probably THE most important command your dog will ever learn. If there is ever a command that could save his life in a terrible situation, I'll bet the recall is it.
I start in a fenced in area and have the dog drag a long line. I let him mooch off and do his own thing. After a minutes I'll call the dog. If he responds, great. Call him back and reward (either with food or a toy --whatever he is motivated by the most works the best). If he doesn't respond, nick the long line AS SOON AS you give the command. Don't be angry if he doesn't respond the first time. Praise in the exact same way you would if he came straight away. Repeat this process again and again and again in the fenced in area EVERY day. Only when he is responding to you 100% in the fenced in area should you progress.
When he is coming reliably in the fenced area, you can move on to an unfenced area. I like to build in the distractions slowly. If you suddenly present a park full of running dogs and people to a dog that has just 'graduated' all his training will go out the window. Distractions MUST be introduced slowly but surely. I would start in a low stimulus area like a field early in the morning --you are aiming to beat the rush. You want some distractions (no matter what time you walk, if its a public area you will see people/dogs at all times of the day) but you don't want to overwhelm the dog.
Use the same principal as before. Keeping the dog on the line, letting him do his own thing, giving the command and rewarding. If he refuses to respond, nick on the line and reel him in.
The recall takes a lot of work but the work is well worth the result. Just think of all the off leash romps you and your dog will able to take...you safe in the knowledge that your dog will come back every time you call it.