The paradox of declining fertility and declining contraceptive use in India: An artefact of survey design?

•Ensuring data quality in large scale surveys is challenging.•The trend and pattern of declining fertility and declining contraceptive use in India is puzzling.•Interview privacy setting and interviewer effect can partially explain the anomaly.•Large scale surveys impose severe demands on survey supervision and ability to ensure privacy.•Innovative ways of data collection for sensitive issues can be explored for proper reporting.