In my endeavor to learn forecasting and improve my statistical knowledge, I've decided to forecast the population of a certain area. I've attached the excel file that I used. I know I'm using excel which is not very common around here. I'm familiar with R but prefer excel for fast analysis such as this.
The collected data is for 1921 to 2009. The forecast period is between 2010 and 2019. I did:
- Arima over all the data
- Arima over the last 10 years or so of the data
- Linear regression over the whole time period
- Linear regression over the last 10 years
- Fitted model using Eureqa software
- Average of above models without the overall linear regression.
The forecast worksheet includes all the raw data, while the forecasting simplified worksheet includes the simplified chart to better view the results.
The question, what are some of the ways I can validate and/or calibrate my forecasts, numbers, assumptions, and improve my analysis from an amateur level to something that is more professional.