Forum Discussion

Alan Amont's avatar
Alan Amont
Copper Contributor
Feb 01, 2017

Forecast returning negative values

Hello Excel community-thank you for your time and help.  I did a forecast for population and the first figure it forecasted was decreased by almost 2%.  Is that normal?  There were 2 years in the historical data where the population figures decreased.  The rest of the forecasted figures were normal.

Formulas & Functions
Need Help

2 Replies

  • Nolan Tripp's avatar
    Nolan Tripp
    Copper Contributor
    Feb 08, 2017

    Alan - The https://support.office.com/en-us/article/Forecasting-functions-reference-897a2fe9-6595-4680-a0b0-93e0308d5f6e?ui=en-US&rs=en-US&ad=US#_forecast.ets at the bottom of this message is a good place to start on your forecast math journey. The different forecast functions are described and there is a workbook with examples. I noodled with some existing data and I could change enough data points to force the first period of forecast data be less than the last period of actual but I didn't dig deep enough to understand the math (lunch break is over). Good Luck!

     

    https://support.office.com/en-us/article/Forecasting-functions-reference-897a2fe9-6595-4680-a0b0-93e0308d5f6e?ui=en-US&rs=en-US&ad=US#_forecast.ets

  • Wyn Hopkins's avatar
    Wyn Hopkins
    MVP
    Feb 06, 2017

    Hi Alan

     

    We'd really need some more information.

     

    Can you expand (be a bit more specific) on what you are doing and what you think the problem is

     

    Thanks

     

     

Resources