Fiscal resources are important regardless of the state you examine. The North Dakota Legislature meets on a biennial basis so I might make the argument an understanding of the fiscal revenue generation process is even more important in some ways.
From a purely statistical perspective the biennial nature makes the seasonality of revenue generation interesting. For a first look at things I broke out the data for the total revenues by month of the biennium. The biennia run from July an odd number year through June of the next odd number year, so July of 2003 to June 2005 as an example. For interpretation purposes then month 1 is The first July of the biennium, month 13 would be the second July of the biennium, and you can fill in the rest.
There are some seasonal patterns here with spikes in tax revenues in biennium month 10 and 13 for many of the biennia. It also appears, generally, more recent biennia see higher monthly total revenues. One other interesting feature comes from the data for the 2011-13 and 2013-15 biennia where month 19 (January of the second year of the biennium) spikes not seen in the other biennia. Large transfers from other state entities account for the high numbers at the beginning and end of the data.
After observing and testifying in front of state government over the years it is very clear they are interested in the overall revenues generated, really looking for where they will be at the end of the biennium. It only makes sense since they set spending priorities and state agency budgets looking across the biennium. With that in mind I generated the cumulative total tax revenues by biennium month for each biennium in my sample.
First impression is there appear to be two distinct collections of lines. The earliest four biennia are clearly on a lower level and perhaps even growth rate compared to the later part of the sample. These factors are evident when we look at the dollar values at the 10 month mark. For the earliest four biennia they are just around the $1,000 million (or $1 billion) mark in total accumulated tax revenues. For the later grouping they are all at or above (roughly) the $2,000 million ($2 billion) in accumulated revenues. The end points of the two groupings are significantly higher too. With these distinctions I generated the graph again but only when from the 2013-15 biennium and later.
What do we see from this graph? The accumulated total tax revenues of the 2013-15 biennium clearly set the pace for the others. In fact it is only the 2019-21 biennium that came close to 2013-15, with some significant catching up late in the biennium. Also the 2021-23 biennium (the current biennium) is on the dame path, for the most part, as 2019-21, though the late gap closure might be in question at this point given broader economic trends. I will obviously keep track of this as the data becomes available over time and project out or forecast some possible paths.