The South Dakota Retailers Association lists monthly sales tax revenue reports from January 2004 up to October 2014. According to those numbers, monthly sales tax receipts decreased over the corresponding month in the previous year in 5 out of 46 months of Dennis Daugaard's gubernatorial regime, or just under 11% of the time. Sales tax receipts shrank in 13 out of the 84 months listed for the Mike Rounds regime, over 15% of the time. Note that 10 out of those 13 shrinky months were in 2009, when the national recession caught up with South Dakota's economy.

But let's compare apples to apples with the available data. During the Rounds regime, from January 2004 to October 2006, the average year-over-year monthly sales tax growth was 6.51%. During the Daugaard regime, from January 2012 to October 2014, that growth has been 4.83%. In 24 out of 34 months in these comparable periods, sales tax receipts grew faster under Rounds than under Daugaard.

I invite Sunday economists of all stripes to pass this chilly winter day brewing up explanations for the underperformance of Daugaardonomics.