Re: notably National Living Wage @AC
I think you missed out a * 52.
What you've done is worked out the weekly increase in the total wage bill, not the annual increase. So,
30K (number of NLW employees) * 0.33 (hourly increase) * 40 (hours per week) * 52 (weeks per year) = 20,592,000 (yes, that's over 20 million.)
Divide by 300,000,000 and multiply by 100 to get percentage = 6.9%
This is still quite small, but more than the insignificant figure you quoted, and definitely more than the annual rate of inflation. A business cannot take even this loss of profit for a number of years without it having an effect (on the dividend and share price, at least).
In practice, what is happening is that people above NLW are not getting any increase until the rising NLW reaches their wage, at which point they will be swept up, and I predict that we will see the number of jobs that are at, or close to NLW significantly go up over the next few years.