Introduction

For a market research expert, the term “incidence rate” might be as routine as morning coffee. However, for those outside the sphere, it may sound more like epidemiological jargon. The truth is, incidence rate in market research is a powerful tool, shedding light on the feasibility, costs, and approaches of a project. Let’s delve deep into this essential concept.

What is Incidence rate?

At its core, the incidence rate represents the percentage of respondents who qualify for a specific survey out of all those who were initially contacted. It’s a measure of prevalence. In simpler terms, if you’re looking for people who have purchased a specific brand of coffee in the last month, the incidence will tell you how many out of your total respondents have done so.

Mathematically:

Why is knowing Incidence Vital?

1. Cost Implications: The lower the incidence, the more respondents you’ll need to contact to achieve the desired sample size of qualified respondents. This means a higher recruiting cost.
2. Feasibility of the Study: If your incidence rate is extremely low, it may indicate that the target population is too niche, and the research may not be feasible, or it might be challenging to gather a significant sample size.
3. Time Considerations: A study targeting a group with a lower incidence will typically take longer than one with a higher rate due to the extra time needed to find and survey qualified participants.
4. Survey Design and Screening: Understanding the incidence rate can guide the design of the survey, particularly the screener questions, which determine whether a respondent qualifies for the main survey.

The Implications of Overestimating or Underestimating Incidence:

Overestimating:

If you believe your incidence rate is higher than it actually is, you’ll underestimate the overall effort and cost. You might budget for contacting 1,000 people, thinking 200 will qualify (20% incidence), only to find that just 100 do. Your costs effectively double, and your timeline might be jeopardized.

Underestimating:

On the other hand, if you believe your incidence rate is lower than the reality, you’ll likely be over budget. While this seems like a safe bet, it could mean unnecessary expenditures or wasted time.

The Complexities and Variability

It’s crucial to recognize that incidence rates aren’t static. They can vary based on:

Geography: The incidence rate for luxury car owners might be higher in affluent neighborhoods than in more average income areas.

Time: If you’re surveying people who’ve purchased ice cream, your incidence rate might be higher in the summer than in the winter.

Cultural Trends: A product that’s trending might have a higher incidence rate than when it’s out of fashion.

Participation Rate: No Study has 100% participation rates among the sampled population, therefore leaving the potential for underrepresented groups and non-response bias.

This will ultimately impact incidence if proper sample management measures are not implemented to reach all demographic sub-quota targets.

Getting the Right Incidence Rate

With the potential for variability and the critical importance of an accurate incidence rate, what can a market research expert do to ensure precision?

1. Pilot Studies: Before the primary research, conduct a small pilot study. This gives a preliminary indication of your incidence rate and can help in refining your approach.
2. Historical Data: If you’ve conducted similar studies in the past or have access to industry data, use that as a reference point.
3. Expert Consultation: Consult with peers or market research agencies that might have experience with similar target populations.

The Bigger Picture

While incidence rate is an essential metric, it’s just one of many in the vast toolkit of a market researcher. It’s crucial to view it in the broader context of the study’s objectives, constraints, and desired outcomes. For instance, while a low incidence rate might increase costs, if the study’s results have the potential to significantly boost a product’s market performance, the increased initial research investment might be justifiable.