It does provide a source, if you click on the anchor for the cost, which seems to be the basis for the whole article given that the summary sounds so similar: h

It does provide a source, if you click on the anchor for the cost, which seems to be the basis for the whole article given that the summary sounds so similar: https://www.penguin.co.uk/books/184573/thrive/ https://www.penguin.co.uk/books/184573/thrive/ I'm sure that number conveniently omits continuing costs, and provides no standard for what effective means.