Maximizing Rates of Consent to Record Linkage and Additional Data Collection

All network activities in this fourth thematic area will focus on innovative methodological approaches for increasing rates of consent to record linkage and additional data collection activities (e.g., the collection of biomeasures), including the reduction of interviewer variability in obtained rates of consent, understanding various opinions regarding consent for data linkage, and possible confounding of non-consent to multiple data collection requests (e.g., administrative record linkage and collection of biosocial measures). Methodological innovations in this area will emphasize the reduction of respondent burden, innovative approaches for administering lengthy surveys with multiple types of data collection (e.g., survey and physical measurements), methods for emphasizing the benefits of record linkage, synthesizing prior literature on innovative approaches to obtaining consent, and explaining interviewer variance in consent rates with future training of interviewers in mind.

NIMLAS activities and funding considerations in this thematic area will be heavily weighted toward critical directions for future methodological research in longitudinal studies of aging that have been identified in the working group meetings for this area. These can be found below, and we will generally entertain innovative applications of generative AI technology for each of these critical directions.

Current Critical Directions for Future Research on Maximizing Rates of Consent to Record Linkage and Additional Data Collection:

Burden Exchange: Does communicating to respondents how record linkages can reduce their survey burden improve consent to record linkage?
Consent and Attrition: Does a failure to provide consent predict eventual attrition in later waves?
Consent Burden: What are best practices in exactly how much consent to additional data collection to ask for in a given study?
Differential Consent: What differences exist among socio-demographic subgroups in rates of consent to different linked data products, and what are the mechanisms/reasons for these differences?
Errors in Record Linkage: Among respondents consenting to the linkage of additional data sources to their survey responses, are there errors arising in the record linkage process, due to probabilistic matching or other mechanisms? If so, can we account for these errors in our analytic methods?
Institutional Trust: How does mistrust in governments / institutions impact consent decisions and retention?
Maintaining Privacy: When linking data sources after consent to record linkage has been maintained, what are the most effective strategies for maintaining respondent privacy and limiting disclosure risk in linked survey data products?
Mode Effects on Consent: How do different data collection modes compare in terms of consent rates for requests for additional data collection and/or record linkage? What are some of the mechanisms underlying any differences in rates of consent across data collection modes? What are the implications of these effects for potential mixed-mode strategies to use for obtaining consent to additional data collection requests?

Bibliography

All bibliography entries below are tagged with colored shapes corresponding to the major thematic research areas of NIMLAS. Specific critical topics for future research that the particular product within each area is addressing are provided in text next to the colored shapes.

Data collection methods for improving representation

Addressing increasing attrition rates

New measurement technologies

Consent to additional data collection

Improving measurement in longitudinal studies of aging

Author	Title	Source	Summary	Critical Topics Tag
Liu, S., Sloan, L., Al Baghal, T., Williams, M., Jessop, C. & Serôdio, P. (2024).	Linking survey with Twitter data: examining associations among smartphone usage, privacy concern and Twitter linkage consent.	International Journal of Social Research Methodology, 28(1), 71–85.	This study examined the pattern of consent to linking their survey data with Twitter accounts as a function of socio-demographic characteristics, privacy concerns and smartphone usage among participants in the UK Understanding Society Innovation Panel. Twitter linkage consent was positively associated with the variety of smartphone activities but not with the smartphone activity frequency and The smartphone technical skills. Privacy concern significant affected the Twitter linkage consent. Age and employment status moderated the associations between privacy concern and Twitter linkage consent. The relationship between privacy concerns and consent was more pronounced among younger than middle-age or older respondents. Among those with higher concerns, younger respondents were less likely to consent than their older counterparts, while among those with a low level of privacy concerns, younger respondents were more likely to consent than their counterparts. The negative relationship between privacy concerns and linkage consent was more pronounced among employed than unemployed respondents.	Differential Consent , Consent and Attrition , Maintaining Privacy
Al Baghal, T., Wenz, A., Serodio, P., Liu, S., Jessop, C., & Sloan, L. (2024).	Linking Survey and LinkedIn Data: Understanding Usage and Consent Patterns	Journal of Survey Statistics and Methodology, 12 (5), 1200–1211.	This study examined the consent to linking survey data to LinkedIn accounts among participants in the UK Understanding Society Innovation Panel. An experiment that crossed the placement of consent requests in a questionnaire and the inclusion of a statement about linking importance showed the highest consent rate when making the request early in the questionnaire with an addition of the importance statement. LinkedIn users were not a random subset of the respondents. LinkedIn users were more likely than nonusers to have higher education, to be employed and to use social media actively. Among the users, consenters to the linkage request were more likely to have higher education, to be employed and to use social media actively, compared to nonconsenters. This demonstrates potential compound selectivity issues with education, employment and social media use in survey-LikedIn linked data.	Differential Consent , Consent and Attrition
Jäckle, A., Burton, J., & Couper, M.P. (2023).	Understanding Society: Minimising Selection Biases in Data Collection Using Mobile App.	Fiscal Studies, 44(4):361-376.	This review paper provides a summary of literature on participation in data collection using mobile apps as well as results from a series of experiments conducted in the UK Understanding Society Innovation Panel in relation to invitation to various mobile app studies, from expenditure, to well-being, to cognition and to body measurements. Overall, the results from the experiments are consistent with the literature. Focusing on the participation in app-based studies among the panel respondents, incentives offered mixed results; personalized feedback has no effect; and placing the invitation to app-based studies in earlier part of the survey questionnaires resulted in higher willingness. Contrary to the literature, the length of the tasks on the mobile app had no effect. When the invitation to a spending study was done in person or over a letter, the participation rate was higher among in-person survey participants. The invitation mode did not matter for Web survey participants. The mode of invitation to a body measurement study did not make a difference. Selection bias was observed: an overrepresentation of younger participants and those with higher education achievements; and a study-specific overrepresentation of those who already use similar mobile apps (e.g., an over-representation of respondents who use health apps in a body measurement app study). Moreover, participation in the app-based studies was correlated with indicators of general survey cooperativeness (e.g., item nonresponse).	Differential Consent , Consent and Attrition , Consent Burden , Incentives , Return of Results
Wenz, A., and Keusch, F. (2023).	Guided by the Technology Acceptance Model, we varied study characteristics in a vignette experiment to examine their effect on individuals’ willingness to download a research app on their smartphone.	Public Opinion Quarterly, nfad019. https://doi.org/10.1093/poq/nfad019.	This study explored factors influencing individuals’ willingness to participate in smartphone-based data collection methods. Findings indicate that participants are more likely to engage when they have control over data collection, can review data before submission, receive invitations via postal letters instead of phone calls, and are offered unconditional incentives rather than conditional ones.	Differential Consent , Interview Mode , Incentives
Walzenbach, S., Burton J., Couper M.P., Crossley T.F., and Jäckle A. (2023).	Experiments on Multiple Requests for Consent to Data Linkage in Surveys.	Journal of Survey Statistics and Methodology, Volume 11, Issue 3, June 2023, Pages 518–540, https://doi.org/10.1093/jssam/smab053.	In a context of multiple requests for linking different administrative records, the formatting of the multiple requests (all at once, one per page, one statement for all requests) does not matter, but the order can matter! Less sensitive requests first, more sensitive requests later. This work has primarily focused on admin data linkages; more work is needed on physical measures, biological measures, etc.	Differential Consent
Vine, J., Jäckle, A., Burton, J. et al (2024).	Understanding Society Innovation Panel Wave 16: results from methodological experiments and new data.	Understanding Society Working Paper 2024-11, Colchester: University of Essex	During the IP16 interview, we asked respondents to locate, download, and use the Sea Hero Quest app. Sea Hero Quest is a multi-platform adventure game (available for Apple and Android phones and tablets) that was designed specifically for the Alzheimer’s Research UK charity to help advance the understanding of spatial navigation, and therefore understand one of the first symptoms of dementia… Unlike previous app studies, we did not find that the mode of issue had an effect on the rate of take-up. There was also no statistically significant difference by mode of interview for those who took part online and those who were interviewed face-to-face by an interviewer. Those who were interviewed by telephone were, however, less likely to take part in the app study. We also find that offering a large incentive (£30) rather than a more standard incentive (£10), increased app take-up. It also increased the rate at which those who used the app completed it. This effect was found for those who did not consider themselves gamers, as well as occasional and regular gamers… The larger incentive slightly decreased the average absolute bias for the characteristics examined, but only by a small amount. The biggest barrier to increased participation is still the unwillingness to participate in the additional study.	Differential Consent , Interview Mode , Incentives
Vine, J., Jäckle, A., Burton, J. and Couper, M. P. (2025).	Getting consent to survey in new ways: evidence from experiments about questions by text message in the Understanding Society Innovation Panel.	Understanding Society Working Paper 2025-14, Colchester: University of Essex	Some information cannot (reliably) be collected in annual surveys of panel members. Text messages (SMS) are well-suited to gathering time-sensitive responses, if a large and representative subset of a panel consents to being surveyed in this way. We investigate: (1) What proportion of respondents consent to text message questions? How does that vary by sample cohort, mode, and whether previously asked for consent? (2) What is the effect of consent question placement within the questionnaire? (3) Is bias of the covered sample reduced by re-asking non-consenters at a later wave? (4) What coverage of non-internet users is gained by seeking consent for text message questioning? We use data from experiments within two waves (IP13 and IP15) of the Innovation Panel of Understanding Society: the UK Household Longitudinal Study. For comparisons of subsets, the proportions consenting are reported along with test statistics for group differences. For the mixed-mode experiment, we report both as-treated and intention-to-treat values, as well as instrumental variable analysis to estimate the effect of mode distinct from selection effects. Bias is analysed via differences between proportions in categories in the overall sample and the covered sub-sample. Most respondents consented to questions by text message when first asked (69% in IP13, 74% in IP15). Of those who declined consent at IP13, 55% consented when re-asked two years later. Face-to-face respondents were more likely to consent than web respondents. Slightly more (2.4 percentage points, s.e.1.5 percentage points) respondents consented when experimentally asked late in the questionnaire than early. Re-asking consent not only reduced the proportion of people who had not provided consent, it also reduced non-consent bias, measured across a range of socio-demographic characteristics. Some panel members who never use the internet use mobile phones and consent to receive questions via text message, so this may complement web surveying.	Differential Consent , Interview Mode
Struminskaya, B., Sakshaug, J. W. (2023)	Ethical Considerations for Augmenting Surveys with Auxiliary Data Sources.	Public Opinion Quarterly, Volume 87, Issue S1, 2023, Pages 619–633, 12 July 2023, https://doi.org/10.1093/poq/nfad030.	Survey researchers frequently use supplementary data sources, such as paradata, administrative data, and contextual data to augment surveys and enhance substantive and methodological research capabilities. While these data sources can be beneficial, integrating them with surveys can give rise to ethical and data privacy issues that have not been completely resolved. In this research synthesis, we review ethical considerations and empirical evidence on how privacy concerns impact participation in studies that collect these novel data sources to supplement surveys. We further discuss potential approaches for safeguarding participants’ data privacy during data collection and dissemination that may assuage their concerns. Finally, we conclude with open questions and suggested avenues for future research.	Institutional Trust , Interviewer Trust
Silber, H., Gerdon, F., Bach, R., Kern, C., Keusch, F., and Kreuter, F. (2022).	A preregistered vignette experiment on determinants of health data sharing behavior: Willingness to donate sensor data, medical records, and biomarkers.	Politics and the Life Sciences. Published online before print September 15, 2022. 10.1017/pls.2022.15.	The COVID-19 pandemic has highlighted the importance of high-quality health research and data for use in political decision-making surrounding population health issues. Therefore, it is important to understand factors such as social trust, privacy concerns, technical affinity, altruism, age, and device ownership, as they either encourage or deter people from sharing their health data.	Institutional Trust , Data Donation , Differential Consent
Silber, H., Breuer, J., Beuthner, C., Gummer, T., Keusch, F., Siegers, P., Stier, S., and Weiß, B. (2021).	Linking surveys and digital trace data: Insights from two studies on determinants of data sharing behavior.	SocArXiv. 10.31235/osf.io/dz93u.	Combining survey and digital trace data from sources such as Facebook, Twitter, Spotify, and smartphone health applications can enhance the richness and quality of the overall data. Using incentives is shown to increase the likelihood of a participant agreeing to share digital trace data.	Differential Consent , Incentives
Sakshaug, J., Tutz, V., and Kreuter, F. (2013, June).	Placement, wording, and interviewers: Identifying correlates of consent to link survey and administrative data.	In Survey Research Methods (Vol. 7, No. 2, pp. 133-144).	In a telephone setting, better to place linkage consent requests at the beginning of the survey; cognitive load gets higher as the survey goes on, so it is important to ask earlier. Interviewer effects can also be quite strong on consent requests, and can depend on interviewer attitudes to linkage consent. Interviewers who themselves would consent tend to have higher consent rates.	Differential Consent , Interviewer Trust , Interview Mode
Sakshaug, J.W., Hülle, S., Schmucker, A., and Liebig, S. (2020).	Panel survey recruitment with or without interviewers? Implications for nonresponse, panel consent, and total recruitment bias.	Journal of Survey Statistics and Methodology, 8(3), 540-565.	Interviewers can have very strong effects on record linkage consent rates (and potentially consent bias), and additional studies of explanations for these effects are needed.	Differential Consent , Interviewer Trust
Sakshaug, J.W., Hülle, S., Schmucker, A., and Liebig, S. (2017, August).	Exploring the effects of interviewer-and self-administered survey modes on record linkage consent rates and bias.	In Survey Research Methods (Vol. 11, No. 2, pp. 171-188).	In an effort to reduce data collection costs survey organizations are considering more costeffective means of data collection. Such means include greater use of self-administered interview modes and acquiring substantive information from external administrative records conditional on respondent consent. Yet, little is known regarding the implications of requesting record linkage consent under self-administered survey modes with respect to consent rates and consent bias. To address this knowledge gap, we report results from a linkage consent study in which employees in an employment survey were randomly assigned to an intervieweradministered (face-to-face) or self-administered (mail/web) interview, which included a consent question to link to federal employment records. We observed a strikingly lower linkage consent rate in the self-administered (53.9 percent) versus the interviewer-administered (93.9 percent) survey mode. However, the impact of survey mode on linkage consent bias was much less severe: survey-measured correlates of linkage consent did not interact with mode and relative consent biases in the linked-administrative variables tended to be small (less than 6 percentage points) under both mode groups; though, linkage consent biases in the administrative variables were larger in the self-administered mode group compared to the intervieweradministered mode group, on average. We discuss the implications of these findings for survey practice and speculate on their possible causes.	Differential Consent , Interview Mode
Mneimneh, Z. (2022).	Evaluation of consent to link Twitter data to survey data.	Journal of the Royal Statistical Society: Series A (Statistics in Society), 185(S2). doi:10.1111/rssa.12949.	Data from social media platforms such as Twitter can be very useful when it is linked to survey data, as it provides a vast amount of information on the thoughts and opinions on various topics of those who utilize these platforms, and do so in almost real-time. Due to privacy requirements, additional consent from respondents is needed in order to link their Twitter data with survey data. This study found that consent rates are higher if the request is placed at the beginning rather than the end of the interview or survey. Additionally, there are many additional individual-level factors that impact consent to data linkage.	Differential Consent
Mitchell, J. and Jackle, A. (2025).	Asking panel respondents to complete additional data collection tasks: Which types of tasks increase panel dropout and which types of respondents are we more likely to lose?	Paper presented at the 2025 conference of the European Survey Research Association, Utrecht, Netherlands, July 2025.	Surveys are increasingly asking respondents to complete additional data collection tasks that go beyond completing survey questionnaires. These might include tasks embedded within the survey, such as consents for data linkage, and tasks respondents have to complete after the interview, such as a diary or mobile app. In previous research we have started to examine the cumulative effects of such additional tasks on dropout in a panel survey. Our findings suggest that each invitation to an additional task increases the probability of drop out by on average two percentage points. This suggests that asking respondents to complete additional data collection tasks might be detrimental to panel surveys. In this paper we examine (1) which types of additional tasks increase dropout from annual interviews of a household panel, and (2) which types of respondents are more likely to drop out from the panel if they are invited to additional tasks. We use data from 15 additional tasks across 16 waves of the Understanding Society Innovation Panel. This is a clustered and stratified sample of approximately 1,500 households in Great Britain with refreshment samples added about every three years. The 15 additional tasks include data linkage consent questions, mobile app studies, bio measures and samples, a time-use diary, monthly surveys, and consent to send survey questions by SMS. Our analysis sample includes 6,712 sample members who completed at least one of the annual interviews. Using these data, we will conduct survival analyses to determine which types of tasks increase the probability of subsequent dropout from the panel and which types of people are more likely to drop out due to additional tasks. The findings will contribute to decisions on how best to gather data on different concepts using different methods, in a way that sample members will cooperate.	Consent and Attrition
Keusch, F., Struminskaya, B., Antoun, C., Couper, M.P., and Kreuter, F. (2019).	Willingness to participate in passive mobile data collection.	Public Opinion Quarterly, 83, 210-235. 10.1093/poq/nfz007.	The increase in smartphone usage and improvement in related technologies provides researchers with a unique opportunity to collect data from users through passive data collection with smartphone applications. Participant’s willingness to participate in passive mobile data collection is often contingent upon the following: the incentive promised for study participation, sponsor of the research, length of data collection period, option to opt out at any time, and ensuring participants privacy will be maintained.	Institutional Trust , Incentives , Differential Effectiveness of New Technologies
Keusch, F., Pankowska P.K., Cernat, A., and Bach, R. L. (2024).	Do You Have Two Minutes to Talk about Your Data? Willingness to Participate and Nonparticipation Bias in Facebook Data Donation.	Sage Journals, Volume 36, Issue 4, January 2024. https://doi.org/10.1177/1525822X231225907	Data donation is a novel approach to collecting digital trace data, where users are asked to download their retrospective data from a platform and share them with the researchers. Little is known about the willingness to donate data and the potential bias that may arise from nonparticipation. We conducted a study among over 900 German Facebook users asking them to donate two data packages. While around 80% of participants were willing to donate their data, only around one-third of them successfully did so. Trust in researchers positively correlates with willingness and donation success, and trust in Facebook is negatively associated with donation success. The framing of the data donation request did not affect the outcomes. We find no difference in frequency of Facebook use between donors and non-donors.	Institutional Trust , Data Donation
Keusch, F., Leonard, M.M., Sajons, C., and Steiner, S. (2021).	Using smartphone technology for research on refugees – Evidence from Germany.	Sociological Methods & Research, 50, 1863-1894. 10.1177/0049124119852377.	Surveying transient and other hard-to-reach populations can be especially difficult. In an effort to increase data collection in a group of refugees, a mobile app was offered after an interview in an attempt to collect additional passive data. Unfortunately, many refugees did not install the app, and low literacy rates are highly correlated with app nonparticipation. On the contrary, introducing an incentive was shown to significantly increase participation in the passive data collection efforts.	Differential Consent , Incentives , Differential Effectiveness of New Technologies
Jäckle, A., Burton, J., Couper, M. P., Crossley, T. F., and Walzenbach, S. (2023).	Survey Consent to Administrative Data Linkage: Five Experiments on Wording and Format.	Journal of Survey Statistics and Methodology, smad019. https://doi.org/10.1093/jssam/smad019.	This study aimed to understand how different aspects of consent request design in surveys can impact informed consent rates for linking survey data to administrative records. In order to do this, a series of experiments including factors such as readability, placement, default options, additional information, and trust priming were varied. The findings suggest that asking for consent early in the survey and priming respondents to consider their trust in the data holder can increase consent rates without compromising understanding, while factors like default wording and offering additional information did not significantly impact consent rates.	Burden Exchange , Differential Consent , Institutional Trust
Jäckle, A., Burton, J., Couper, M.P., Crossley, T.F., and Walzenbach, S. (2022).	How and Why Does the Mode of Data Collection Affect Consent to Data Linkage?	Survey Research Methods, 16(3), 387–408. https://doi.org/10.18148/srm/2022.v16i3.7933.	We use experimental mixed-mode data from a probability survey in Great Britain to examine why respondents are less likely to consent to data linkage in online than face-to-face interviews. We find that the 30 percentage point difference in consent rates is a causal effect of the mode on willingness to consent; it is not due to selection of different types of respondents into web and face-to-face interviews. We find that respondents are less likely to understand the data linkage request, less likely to process the consent request thoroughly, and more likely to be concerned about privacy and data security when answering online rather than in a face-to-face interview. Using digital audio-recordings of the face-to-face interviews, we find that verbal behaviours of interviewers do not explain the mode effects: respondents only rarely ask questions or express concern, and interviewers only rarely offer additional information about the data linkage. We also examine which devices respondents used to complete the web survey and find that these do not explain the mode effects either. Finally, we test the effects of simplifying the consent request, by reducing the reading difficulty: while the easier wording increases understanding of the request, it does not increase consent in either mode.	Differential Consent , Burden Exchange , Interview Mode
Jäckle, A., Beninger, K., Burton, J. and Couper, M.P. (2021).	Understanding Data Linkage Consent in Longitudinal Surveys.	In Advances in Longitudinal Survey Methodology, P. Lynn (Ed.). https://doi.org/10.1002/9781119376965.ch6.	Linking data from longitudinal surveys to administrative records (whether held by government or private entities) is an increasingly attractive option for several reasons. As longitudinal surveys continue to respond to pressures to increase efficiency, and as new survey modes are developed, the use of mixed-mode data collection is increasing. Much of the work on informed consent for administrative data linkages has focused on exploring correlates of consent at both the respondent and interviewer level and examining non-consent bias. In this chapter, the authors focus on understanding the process by which respondents decide whether to give consent. They use both quantitative analyses of existing data from Understanding Society and qualitative work to explore the consent process. The quantitative analyses document the extent to which respondents make consistent decisions, and the extent to which the mode of data collection affects this decision, by addressing some research questions.	Differential Consent , Burden Exchange , Interview Mode
Imke Herold, I., Pettinichi, Y., and Bethmann, A. (2024).	Comparative Analyses of Consent Rates in the Survey of Health, Ageing and Retirement in Europe (SHARE)	Paper presented at the 2024 Comparative Survey Design and Implementation Workshop, Berlin, Germany.	This presentation provides an overview of an NIMLAS pilot study that aims to examine consent patterns from multi-national, multi-lingual, multi-cultural contexts of the Survey of Health, Ageing and Retirement in Europe (SHARE).	Differential Consent
Crossley, T.F., Burton, J., Couper, M.P., Jäckle, A., and Walzenbach, S. (2025).	Can we nudge respondents to process data linkage consent requests more carefully? If so, does this increase consent in surveys?	Paper presented at the 2025 conference of the European Survey Research Association, Utrecht, Netherlands, July 14, 2025.	The work presents results from the first experimental effort to induce reflective decision making in deciding whether to respond in the positive to survey requests for consent to record linkage. The results of the experiment suggest that efforts to induce reflective decision making when asking for consent to record linkage did not have any meaningful effect on decision processes, and may have actually had negative effects on consent outcomes.	Differential Consent
Crossley, T. F. (2024).	Using paradata to help understand consent to record linkage
Burton J., Couper, M. P., and Jäckle, A. (2024).	The Effects of Placement and Order on Consent to Data Linkage in a Web survey	Journal of Survey Statistics and Methodology 2024, smae004. https://doi.org/10.1093/jssam/smae004.	We report on an experiment in a supplemental web survey as part of a longitudinal study in the United Kingdom where we ask survey respondents to consent to two forms of data linkage to health records and to consent to be mailed a serology kit. We varied the placement (early, early in context, or late in the survey) and order (linkage first or serology first) of the consent requests. We also examine reasons for consent or non-consent. We find that order of the requests does not make much difference, but making the requests early in the survey significantly increases consent rates over asking them after a series of content-related questions (by 3.4 percentage points) or later in the survey (by 7.2 percentage points). This is consistent with previous research showing that early requests for consent in a survey have a positive effect. The main reason chosen for not consenting related to the personal nature of the information requested.	Differential Consent
Burton, J., Couper, M. P., Crossley, T. F., Jäckle, A., & Walzenbach, S. (2025)	How Do Survey Respondents Decide Whether to Consent to Data Linkage?	Sociological Methods & Research. DOI: https://doi.org/10.1177/00491241251344289.	Linkages between surveys and administrative data provide an important opportunity for social and health research, but such linkages often require the informed consent of respondents. We use experimental data collection across five different samples to study how consent decisions are made. More reflective decision processes are associated with higher rates of consent, greater comprehension of the proposed data linkage, and greater confidence in the decision, but only about a third of respondents report using a reflective decision process. This suggests that the provision of additional information is unlikely to lead to significant improvements in informed consent.	Burden Exchange , Differential Consent
Burton, J. (2025).	Remote collection of biomeasures in Understanding Society: The UK Household Longitudinal Study	Paper presented at the 2025 conference of the European Survey Research Association, Utrecht, Netherlands, July 2025.	This presentation provides an overview of recent efforts in the Understanding Society study to collect biomeasures, including methodological and design implications. The author reports that it is possible to collect biomeasures with interviewers and participant self-collection, and that 1) return of samples is lower on web; 2) return is positively affected by offers of feedback; 3) participants can provide their own BP, waist/hip measures; and 4) there is measurement error, but this can be corrected using validated measures from interviewers. They are in the pilot stages of collecting additional biomeasures.	Consent Burden , Differential Consent
Beuthner, C., Weiß, B., Silber, H., Keusch, F., & Schröder, J. (2024).	Consent to data linkage for different data domains–the role of question order, question wording, and incentives.	International Journal of Social Research Methodology, 27(4), 375-388.	This article compares consent to data linkage requests for seven data domains: administrative data, smartphone usage data, bank data, biomarkers, Facebook data, health insurance data, and sensor data. We experimentally explore three factors of interest to survey designers seeking to maximize consent rates: consent question order, consent question wording, and incentives. The results of the study using a German online sample (n = 3,374) show that survey respondents have a relatively high probability of consent to share smartphone usage data, Facebook data, and biomarkers, while they are least likely to share their bank data in a survey. Of the three experimental factors, only the consent question order affected consent rates significantly (with earlier consent requests associated with higher consent rates). The likelihood of consent further decreased with each additional request, showing that respondents may have the feeling of increasing privacy costs with every additional linkage of data they allow.	Consent Burden
Anton van Erkel, P.F., Hopmann, D.N., Skovsgaard, M., and Terren, L. (2024).	The Role of Consent Form Design Under GDPR: A Survey Experiment	International Journal of Public Opinion Research, Volume 36, Issue 1, Spring 2024, edad047,. https://doi.org/10.1093/ijpor/edad047.	This experimental study of alternative approaches to obtaining informed consent in the GDPR context of the European Union documents the advantages, for survey response rates, of using condensed information and in-text legal references (as opposed to a hyperlink).	Consent and Attrition , Maintaining privacy
Al Baghal, T. (2023).	Linking survey and social media data: Experiences and Evidence.	Presentation to the University of Michigan Survey Research Center, December 2023.	We report on an experiment in a supplemental web survey as part of a longitudinal study in the United Kingdom where we ask survey respondents to consent to two forms of data linkage to health records and to consent to be mailed a serology kit. We varied the placement (early, early in context, or late in the survey) and order (linkage first or serology first) of the consent requests. We also examine reasons for consent or non-consent. We find that order of the requests does not make much difference, but making the requests early in the survey significantly increases consent rates over asking them after a series of content-related questions (by 3.4 percentage points) or later in the survey (by 7.2 percentage points). This is consistent with previous research showing that early requests for consent in a survey have a positive effect. The main reason chosen for not consenting related to the personal nature of the information requested.