The rise of online shopping has led to an environmental health hazard for neighborhoods bordering the large warehouses (i.e. fulfillment centers) that facilitate the delivery of goods purchased on the Internet.The hazard stems from the large number of diesel-powered trucks that pass through the neighborhoods as they enter and leave these massive distribution centers.The nitrogen oxide emissions of these vehicles exacerbate respiratory conditions, such as asthma, and even lead to early death.Some of the worst-hit areas of the country for this hazard (e.g. Southern California) are now proposing regulations that would require companies running these centers (e.g. Amazon) to make investments in emissions-reduction technologies or alternatively pay a penalty for the harm caused to nearby communities.

The table below presents the benefits and costs (hypothetical) of a specific example of this type of regulation.Initially, in the first year (Year 0), there would be a significant cost of $100 million incurred, collectively, by companies as they made large investments (e.g. purchasing electric or natural-gas powered vehicles) or paid significant penalties.Gradually, though, over a 10-year period, the costs would decline.In contrast, the benefits of this regulation (in the form of improved health, labor productivity, and saved lives) would gradually increase over 10 years.All of the future (i.e. after Year 0) benefits and costs associated with the regulation (in millions of dollars) are in the table below (columns B and C).Column D in the table shows the net benefit (B minus C) realized at the end of each year.