In the city of Seattle, for example, every year, companies over a certain number of employees are required to participate in an annual transportation survey. The employees are surveyed. The questions ask how far the employee commutes to work, how long it takes, and by what method (private vehicle, car pool, public transportation), how many days a year they work from home, or take off, etc. The effort is to assess the impact on environment, parking infrastructure, public transportation, roads, etc.

Obviously, there isn't a 100% response rate so the data is extrapolated from the responses to the total number of employees employeed at that site (probably why they only poll companies of a minimum size and larger).

If they wanted to implement something like this in seattle, then the next step would be to take the data they already have and start sending those companies a new bill for a new annual tax based on the assessment.

Lots of taxes work off of an estimated assessment rather than having to account for every nut snd bolt of the thing (property taxes, for example).

So how do you do it? That's how you do it. This isn't rocket science, and you don't need to invent new accounting methods or worry about the accounting-sky falling to accomplish it.

Modern accounting techniques are amazing and super effective,

Hmm

The biggest weakness of accounting though is its inability to capture externalities

Oh so you mean it's actually dog shit then, if you can't properly look at external risks outside the clearly defined formulas and can game said fomulas to cook books to one's liking.

How does one company record the cost of their employees commute? How do you even begin to calculate that? How do you measure the cost of extra leukemia cases in a town ten years after a train derails nearby? How do you record that in your books? How do you calculate and record the distress these huge noisy shipping vessels cause whales? It's just so subjective and impractical.

You act like these are difficult tasks in the modern era. Commute is pretty simple, what type of vehicle, what are its maintenance costs at certain mileages, what are the crash statistics, etc. Once you have a general fomula you can add an increased payout to cover ireegular externalities to properly hedge against the edge cases. Same shit for the others. It's not subjective and impractical, it's just not the going to be perfectly effiecnt as you need to create a bigger financial bubble to account for edge cases. The problem is hyper fixation on extracting the most captial possible from a business. Stop trying to be the most clean cut business and focus on aiding your communities, working to better infrastructure and stop interference with local governments for tax benefits. Then progressive changes can be beneficial to both and reduce external unmitigated risks as we have a more nuanced model to work with.