Publisher Summary This chapter focuses on projection techniques, which are quantitative methods used for estimating the future. Techniques to project the future are essential for making plans and for most policy decisions. The chapter reviews two types of quick and easy to use techniques to project future levels of population, employment, economic output, or other activities based on past levels of those measurements or activities. Those techniques are designed to provide reasonable projections of future levels of measurements or activities. Those two techniques are trend extrapolation projection models and ratio projection models. Good historical data are necessary for trend extrapolation projection models. Extrapolation projection models examine the historical data using a time-series plot. The trend extrapolation projection models discussed in the chapter are linear (straight line) projection model, exponential projection model and modified exponential projection model. The ratio projection models are used when it is decided to base the projection on an already prepared projection for some other entity.