E-commerce is coming for your job

Not all retail employees are threatened by online sales, but millions are.

Retail stores are nearing a tipping point, especially in the United States where retail floor space dwarfs other countries.

The US has 23 sq feet per capita of retail space (but as much as 46.6 sq feet). It's difficult to come by reliable numbers, but that compares to 14 sq feet in Canada, 6.5 sq feet in Australia, 2.3 sq feet in France and 1.1 sq feet in Italy.

In short, retail floor space is a bubble and ecommerce is going to pop it.

Goldman Sachs is out with a note underscoring how much more efficient selling online is. It takes 0.9 employees to generate $1m in sales online and 3.5 employees in a brick-and-mortar store.

How many jobs will be lost as sales shift online? About 10% of the US workforce is in retail sales -- more than 15 million people. Of those cashiers and salespeople represent about half.

There are a total of 7.2 million people currently unemployed in the US. Ultimately, things like books and electronics are easier to sell online so not all sales will move online. But say one-third of retail jobs disappear and already unemployment climbs to 7.5% from 4.5%.

Tack on the jobs lost from other types of automation and driverless cars and it's a small insight into the scope of the problem.