See also https://thezvi.wordpress.com/2017/09/30/slack/ https://thezvi.wordpress.com/2017/09/30/slack/ , which makes the point that slack and efficiency are not

See also https://thezvi.wordpress.com/2017/09/30/slack/ https://thezvi.wordpress.com/2017/09/30/slack/ , which makes the point that slack and efficiency are not opposites: "Slack prevents desperation. You can avoid bad trades and wait for better spots. You can be efficient."