The Nordic Ways - Swedish ss last names and more.
Article with the maps at GP is in Swedish, but you can translate. Hoover over each municipality to see where the most people are named Johansson, Andersson and Eriksson.

In America the same year Sven Göran Eriksson chocked Europe and won the UEFA cup with a bunch of amateur players in IFK Göteborg, 1982. An american Mall salesman first refused to print my name on the back of a Baseball jersey I was about to purchase, with the argument, what kind of spelling is that. He claimed that Ericson was the right spelling. After showing him my passport he gave up and I got my Eriksson jersey.
Up until late 19th century Sweden did as they do on Iceland. Took their daddy's name in my case, as a dad, Per it would be then added sson. Persson. On Iceand they add dottir (daughter), Persdottir that would be or rather Persdotter.
But authoroties thought is was hard to handle so they made it a Statutory instrument in 1901. And became a law in 1963. Which said you can't take a name that can be misstaken for a train station for instance.
But as you maybe noticed, we can spell with a single s as well. Eriksson, Ericsson, Erikson and Erixon is spelling you can see. The last spelling is mostly found among Art painters and Hockeyplayers.
But Eriksson is not as common as you might think Phone companies and Football coaches aside.

I grew up in Johansson land. I think I had three Johansson in my class in grade school. Now I live in Andersson land but in a municipality that have Eriksson as the most common name. I wonder If my moving here changed it or if we are in a big lead?
Skåne have Nilsson as most common. Note that Denmark have Nielsen as most common last name.
Is this reflected in Swedish Nordic Noir stories?
Seldom. The ambitious people don't want to be a sson. They want to be a -ius, -lund, -fors, -ander, -fjäll or else. Salachenko strips off the Russian chenko (with different western spellings) and becomes Sala-nder. Salander.

was named Wallander because Mankell's method of randomly choose a name in the telephone catalog.
Sources. Except the GP article also SCB.se, Babyhjälp.se and Wikipedia.se and a interview with Henning Mankell on DVD bonus materials.