My very strong gut feeling is that leashes are for animals, NOT people, including children. I absolutely hate seeing them and believe they are inhumane. I have four children, now ages 8 to 17. So I have had experience with kids not wanting to stay with you and running away. I discovered by accident that children understand what we say at very young ages and able to comply with what we expect if we tell them/remind them of the rules. So I would remind him before you leave the house what the rules are, like no running around, stay with mommy (my kids often had to hold my shirt, so I knew where they were, especially when I was carrying another child.) When you get to there ask him to restate the rules. If there was misbehaviour you can remind him of the rules/ask him again what the rules are. If he continues to misbehave then you need to have consequences, ie. time out or whatever you think is best in the situation, for example if you went to get him something then you don't buy it during that trip. You need to be prepared to leave if he can't follow the rules - I know it can be very difficult especially when you feel you need to get things done, but it will pay off in the long run. I NEVER bribed (sp?) my kids for good behaviour. Good behaviour is expected (of course all kids misbehave at times, but it's about setting your expectations for their behaviour) I think sometimes we forget that kids don't automatically know what we expect or where we are taking them. I would start out a trip telling my kids all the places we had to go and what behaviour I expected of them. Kids also have short attention/memory/get distracted easily and we need to remind them or get them to refocus. For awhile you may need to keep trips short - so he can be "good". If the time frame is too long you will set him up to fail. Sorry, I don't remember when this behaviour is outgrown, but this too shall pass. Hang in there!