Nothing causes akrasia. There is no such thing as akrasis. 'Akrasia' is the label you apply to a phenomenon you don't understand and you really need to think about more deeply.

It would probably help if you pointed out that the reason we have the illusion of akrasia is because people's built-in systems for modeling the intentions of other people, generate mistaken predictions about motivation and decisions when applied to one's self. It's sort of like looking at yourself in a funhouse mirror, and mistakenly believing you're fatter or thinner than you actually are.

In reality, it's not that you don't follow through on your will, it's that you've failed to understand (or even observe) how your behavior works in the first place, let alone how to change it. Most descriptions of akrasia and how to deal with it (including what I've read of Ainslie's so far), strike me as trying to explain how to steer a car from the back seat, by tying ropes to the front wheels, or by building elaborate walled roads to keep the car going in the right direction.

It makes me want to scream, "but you're not even looking at the dashboard or touching the controls!" Those things are not even IN the back seat.

They're looking for information in the human parts of the mind, while entirely ignoring the fact that the secrets of our behavior and decisions CAN'T be there, or animals couldn't live their entire lives without ever having a single rational, logical, or "economical" thought.

Thought is not the solution here, it's the problem. And the answers are in the FRONT seat -- in the mind-body connection. In emotions, and their somatic markers. In the internal sensory (not verbal!) representations of available choices and expected outcomes. All that equipment that was (evolutionarily) there LONG before the back-seat driver showed up and started critiquing which way the car is going.

And the back-seat driver is only confused because he thinks he's the one who's supposed to be driving... when he's really only there to wave out the window and yell at the other drivers.

And maybe persuade them... that he knows where he's going.