Norway's cross-border commerce increased by nine percent to 14 billion Swedish kronor in 2011, according to figures from Norwegian statistics agency SSB, with 94 percent of the trade consisting of one-day shopping trips to Sweden.
The trend has caused concern among Norway's business community as well as with the Norwegian state, which last year lost an estimated 3 billion Swedish kronor worth of revenues in taxes and fees.
"We're concerned because this is a huge amount of turnover that Norwegian traders miss out on. They and their supplier are losing lots of jobs," Thomas Angell of the Norwegian business trade association Virke Handel told Norwegian news agency NTB.
According to his estimates, Norwegian firms have lost around 10,000 jobs as a result of Norwegians taking their business to Sweden.
Just over half of Norwegians' spending in Sweden, 52 percent, takes place in Strömstad and Svenesund in Bohuslän in southwestern Sweden.
Charlottenberg and Arvika in Värmland County, meanwhile, account for 19 percent.
The trend has even prompted the right-wing populist Fremskrittspartiet to demand a debate about the issue in the Norwegian parliament.
According to SSB's figures, it's not simply cheap booze that attracts Norwegians to Sweden.
And sales statistics from Swedish alcohol store monopoly Systembolaget show that turnover at stores located near the Norwegian border only increased by 0.6 percent, compared with the 9 percent overall increase in cross-border trade.
Another contributing factor may have been the Norwegian butter shortage which took place before Christmas, according to Sten Magne Berglund of the Norwegian temperance association Actis.