- **Stated preference** methods are frequently applied in **environmental valuation** to estimate economic values of policies, goods, and services that cannot be valued otherwise.
- Stated preference methods face **validity challenges**.
- Valid value estimation requires **sufficient information** provision about the good being valued.
- Still unclear **what formats of information** and **how much information** are optimal for valid preference elicitation.
- Still unclear **what formats of information provision** and **how much information** are optimal for valid preference elicitation.
- Too **little information** may lead respondents to **not** being able to make an **informed choice**.
- Valid preference elicitation depends not only on the provision of information, but also on the **appropriate processing and recall** of the information by the respondent.
- **Optional information** allows the respondents to gather required information if needed and might increase efficiency of information provision
- Providing optional information should enhance optimal information seeking leading to less heterogeneity in good-specific knowledge between the respondents
- There is **little research** on the effects of **optional information provision** on choice behavior and information recall.
- In their study, @tienhaara2022information surveyed preferences for agricultural genetic resources, allowing respondents the option to access detailed information on the valued goods prior to preference elicitation.
- Similarly, @hu2009consumers offered respondents the opportunity to access voluntary information about genetic modified food before participating in a choice experiment.
- Similarly, @hu2009consumers offered respondents the opportunity to access optional information about genetic modified food before participating in a choice experiment.
- Both studies conclude that, on average, respondents who voluntary retrieve information have **larger willingness to pay** for the good to be valued.
- Their study design, however, does not allow comparing the optional information retrieval to a version where the additional information was shown obligatory.
1. Do obligatory and optional information provision affect **survey engagement**, **information recall**, **consequentiality**, and **stated preferences**?
- OLS and MXL with interactions
2. Do **socio-demographic** or **attitudinal** variables influence the decision to **access optional information**?
- Logit regression
3. Do **survey engagement**, **information recall**, **consequentiality**, and **stated preferences** differ between respondents who **voluntary access information** and those who do not?
<!-- v_{Treat_B} = \{Treated, Vol. Treated, No Info\} -->
<!-- \end{equation} -->
<!-- ``` -->
```{=tex}
\begin{equation}
v_{Treat_A} = \{Treated, Optional Treatment\}
\end{equation}
```
```{=tex}
\begin{equation}
v_{Treat_B} = \{Treated, Vol. Treated, No Info\}
\end{equation}
```
# Case A: Obligatory vs. Optional Information
## Case A
1. Do obligatory and optional information provision affect **survey engagement**, **information recall**, **consequentiality**, and **stated preferences**?
3. Do **survey engagement**, **information recall**, **consequentiality**, and **stated preferences** differ between respondents who **voluntary access information** and those who do not?
3. Do survey engagement, information recall, consequentiality, and stated preferences differ between respondents who voluntary access information and those who do not?
::: incremental
- Respondents that voluntary access information do engage more in the survey & have a higher consequentiality score
- Respondents that voluntary access information do not engage more in the survey, but perform best in the quiz
- Voluntary information access is negatively correlated with number of status quo choices
- Respondents that decide to not access additional information engage less in the survey, have a lower consequentiality score and do not perform different in the quiz than the non-treated respondents
- Higher willingness to pay values in groups that voluntary access information
- Highest willingness to pay values in the group that voluntary accesses information
:::
## Conclusion
::: incremental
- Obligatory and voluntary information treatments increase information recall and willingness to pay for naturalness of and proximity to urban green spaces
- Exogenous treatments do not affect consequentiality
- Voluntary information access is correlated with increased consequentiality, higher survey engagement and higher willingness to pay
- Obligatory information treatment is more effective than optional on the cost of slightly reduced survey engagement
- Providing optional information does not lead to optional information seeking
- Voluntarily accessed treatment shows strongest effects, but is highly endogenous
- Optional information is mostly accessed by people that are interested in the good to be valued
- Providing optional information seem to rather increase inequality in good-specific knowledge than decreasing it
- We recommend to use obligatory information provision rather than optional one
