The state’s unemployment rate fell to 6.8 percent last month, providing yet more proof that the Bay State economy is performing considerably better than the national economy.

But there is one confusing bit of news: A separate study shows a net decline in the number of payroll jobs last month. You might be thinking: How can that be if the jobless rate is falling? Well, as far as we can determine, the payroll numbers and jobless rate are determined through two different surveys, so they can sometimes have slightly different results.

Still, we’ll take the good news. The trend over the past 18 months has been a slowly improving employment picture in Massachusetts — and the unemployment rate for December follows that pattern.

File under: Glass half full