Regarding the demographic effects, we use the national population data that is available from Statistics Netherlands. This data is available on a monthly basis for recent years. We conjecture that the national population size has a positive effect on the electricity
infeed, however, it is possible that the trend in the national population differs from the trend in the population of the particular provinces in which the DSO operates. To capture the economic effects, we include the national GDP (available from Statistics
Netherlands for every quarter) as a factor in the dataset.We expect that economic growth has a positive relationship with the total infeed, however, it is plausible that the national economic growth may not give a good representation of the economic growth of the provinces in which the motivating DSO operates. Unfortunately, no demographic and economic growth data for the specific provinces Noord and Brabant were available for the relevant time periods.
Hence, we use the national figures as a proxy in our model.