That's the general accounting principle, but accounting is pretty hard. Leases get pretty complicated quicky. For example in a sale and leaseback under IAS17 ev

That's the general accounting principle, but accounting is pretty hard. Leases get pretty complicated quicky. For example in a sale and leaseback under IAS17 even 'profits' you make at the outset (let's call them economic profits), you are only allowed to recognize proportionally to the time of the contrary. Here the precautionary nature beats the realisation principle. Here's an example of how accounting is hard with differences between US GAAP and IFRS [1]. Uber loses half it's revenue under a new US GAAP principle... [1] https://www.ft.com/content/74447ca2-6b0b-11e7-bfeb-33fe0c5b7eaa https://www.ft.com/content/74447ca2-6b0b-11e7-bfeb-33fe0c5b7...