My boyfriend is a heavy smoker, and he smokes a pack a day. How do I convince him that there's no benefits to it, and he can better spend the money elsewhere?

You should calculate the amount of money he could have and show him the figures. By showing the figures, it will hit him harder than just telling him.

I have heard of guys quitting smoking before and all the times, it's because of paternal love toward their children or grandchildren.

They don't want their young to breathe in their second- or third-hand smoke, which is very bad (imagine air pollution every day in the house), so they made the decision to quit. Only love can move mountain.

When they quit smoking, their life span is longer, which means they also get to be their loved ones longer. Good health is responsibility to oneself and to own's family.

Other times when people quit is due to either poverty or extreme poor health.

This is a very, very difficult situation, particularly when he started early.

Some 'drugs' are used somehow as a self-treatment of sorts, so besides an already established dependency on nicotine there could be circumstances that support his continued smoking, like stress at his workplace or social stress.

Also, if he often meets other smokers or lives near to other smokers it is almost impossible to quit because the location (f.ex. own balcony, workplace) where one smoked is a strong unconcious stimulus to smoke again.

Also if other people 'preach' on quitting permanently this could evoke feelings of guilt with him and be counterproductive. Difficult. Maybe both of you visit with a professional stop smoking advisor.

Our rational brain tells us that it is a bad habit, however our deep brain emotional 'animal spirits' often are stronger. We maybe all have a habit we would like to quit, true?

Don't give up easily!

Especially when it is something that does not benefit your loved one.

Maybe you can change a different approach, different from the financial point of view.

Share with him the adverse effects of smoking in the long term. If he has a hobby he loves or loved ones, imagine how smoking will cause him not to be able to do what he like or spend time and energy with his loved ones.