How accurate are self-reports? Not very -- Linking population surveys with gambling operator data

Session Title

Gambling Research: Measurement & Online Patterns

Presentation Type

Paper Presentation

Start Date

28-5-2026 12:00 AM

Abstract

A large share of what we know about human behavior—whether related to health, spending, or addictions—is based on self-reports. But can they be trusted? We combine unique datasets from a population-based survey and operational records from a gambling operator (Veikkaus Ltd.), allowing us to directly compare self-reported behavior with observed behavior. We contrast self-reports on money gambled, number of days played, and number of different game types played with corresponding measures derived from operator data. At the average level, self-reports correspond surprisingly well with reality. However, at the individual level there are large discrepancies: some substantially overestimate, while others substantially underestimate. Although the averages lend credence to the reliability of self-reports, this signal is buried under substantial inter-individual variability: only a small proportion of people self-report accurately. This highlights the need to systematically and repeatedly combine self-reports with objective data.

Author Bios

I'm a cognitive scientist and game enthusiast. I study emotions and decision-making in various contexts, most notably poker, gambling, and games in general. Currently I work at the Finnish Institute for Health and Welfare on gambling harm prevention.

Share

COinS
 
May 28th, 12:00 AM

How accurate are self-reports? Not very -- Linking population surveys with gambling operator data

A large share of what we know about human behavior—whether related to health, spending, or addictions—is based on self-reports. But can they be trusted? We combine unique datasets from a population-based survey and operational records from a gambling operator (Veikkaus Ltd.), allowing us to directly compare self-reported behavior with observed behavior. We contrast self-reports on money gambled, number of days played, and number of different game types played with corresponding measures derived from operator data. At the average level, self-reports correspond surprisingly well with reality. However, at the individual level there are large discrepancies: some substantially overestimate, while others substantially underestimate. Although the averages lend credence to the reliability of self-reports, this signal is buried under substantial inter-individual variability: only a small proportion of people self-report accurately. This highlights the need to systematically and repeatedly combine self-reports with objective data.