Purchase Likelihood Option

The purchase likelihood option estimates the stated purchase likelihood for products you specify in the simulator. Each product is considered independently. If you intend to use the Likelihood of Purchase option in the Market Simulator, your data must be appropriately scaled. The following estimation methods result in data appropriate for the purchase likelihood option:

1.

ACA, if calibration concepts have been asked.

2.

CVA, if single-concept presentation was used, and the logit rescaling option used with OLS regression.

3.

CBC/HB, if calibration concepts have been asked and the CALIB program used to rescale the utilities.

Any other procedure will result in simulations that are not an accurate prediction of stated purchase likelihood. Also keep in mind that the results from the Purchase Likelihood model are only as accurate as respondents' ability to predict their own purchase likelihoods for conjoint profiles. Experience has shown that respondents on average exaggerate their own purchase likelihood.

You may use the Purchase Likelihood model even if you didn't scale the data using calibration concepts, but the results must only be interpreted as a relative desirability index.

The purchase likelihoods that the model produces are not to be interpreted literally: They are meant to serve as a gauge or "barometer" for purchase intent.

This model provides a means of simulating a product category with only a single product. The other three choice models are comparative models that require at least two products to be specified in a simulation. Likelihoods are estimated for product concepts by summing scaled utilities and estimating probabilities with the following transformation:

p =    eu

_____

1 + eu

where,

p = probability of purchase

e = the constant e

u = product utility