An availability design, also known as a cross-effects design, is a special type of labeled design. It is used to understand what happens when an alternative is added or removed. For example:
- If Coke introduces a new variant, will it mainly cannibalize itself, take share from the existing brands in proportion to their market share, or something else?
- If light rail is added to a city, how much will car traffic reduce?
Where availability designs are not used, predictions from choice models regarding the effect of adding or removing an attribute are greatly influenced by statistical assumptions rather than the actual data. (Andreas G. Lazari and Donald A. Anderson (1994), “Designs of Discrete Choice Set Experiments for Estimating Both Attribute and Availability Cross Effects” in Journal of Marketing Research, Vol. 31, No. 3 (Aug., 1994), pp. 375-383.)
The creation and analysis of availability designs is an advanced topic and outside of the scope of this guide. For more information, see Damaraju Raghavarao, James B. Wiley, and Pallavi Chitturi Choice-Based Conjoint Analysis: Models and Designs, 2010, CRC Press.