Extrapolating from regression lines
{"Image DocumentName": "Extrapolating from regression lines", "Image ImageDescription": "A common method is to fit a regression line (or curve) to the historic data and extrapolate it to the future. This is OK for a short time into the future as long as the historic data are stable, ie changing at a steady rate. But: The regression line is fitted across the whole of the historic data, and gives equal weight to all points: e.g. the value for last year is given the same weight as one from 20 years ago \u2013 it doesn\u2019t give the best estimate of \u2018current trends\u2019 We cannot give realistic confidence intervals for future values (\u2018prediction intervals\u2019 or \u2018forecast intervals\u2019)", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}