The impact of electronic gaming machine jackpots on gambling behaviour

Matthew Rockloff, Nerilee Hing, Phillip Donaldson, En Li, Matthew Browne and Erika Langham

What was the research?

This research examined how jackpots, large EGM prizes that pay out infrequently, influence the behaviour of EGM gamblers. The study also examined the effect of jackpot expiry on EGM gambling behaviour. Jackpot expiry refers to where a jackpot is no longer available after a fixed period of time or number of spins. This research was undertaken through Central Queensland University and funded by Gambling Research Australia.

Types of jackpots

Progressive jackpots

The prize amount grows incrementally with every new bet placed

Non-progressive jackpots

The prize is fixed, and does not increase with each bet

Deterministic jackpots

The prize will be payed out after a fixed interval, that is not known to the player

Non-deterministic jackpots

The prize is paid out randomly

Hidden jackpots

The prize amount is hidden from players

Mystery jackpots

The exact combination of symbols that will trigger the jackpot is unknown to the player

Linked or socially networked jackpots

The prize can be won on one of several machines, allowing for higher prizes. This type of jackpot may operate within a venue (local area) or over several venues (wide area).

How was the research conducted?

This study involved experiments using a simulated gaming machine and observations of EGM gamblers in venues.

Experimental EGM gambling

Participants played a simulated gaming machine on a laptop computer, which was programmed to provide a fixed sequence of wins and losses for twenty spins. After this point, all spins would result in a loss.

Participants gambled with real money – the compensation given to them for participating in the study.

The simulation part of the study involved four experiments:

  • comparison of progressive, non-progressive, deterministic and non-deterministic jackpots (123 participants)
  • examination of hidden and mystery jackpots (107 participants)
  • simulation of linked jackpots (114 participants)
  • simulation of jackpot expiry (130 participants).

Each of the experiments was designed to allow comparisons between the types of jackpots studied. The researchers measured average bet size, speed of betting, total spins played and final payouts.

The researchers also asked about the player's overall enjoyment of the session. In some experiments, the researchers also measured physiological arousal as a result of the gambling.

Observed EGM gambling

The researchers followed 234 participants as they gambled in three Queensland gaming venues. The researchers observed machine characteristics, including jackpots available on the machine, and play characteristics. Half of the participants were primed to think about winning a jackpot before the observations.

What were key findings of the research?

The experimental component of this research found that:

  • large jackpots were associated with larger bet sizes in several of the experiments
  • players placed the largest bets on EGMs that were deterministic and non-progressive suggesting that high-value deterministic jackpots may encourage more intensive play
  • large jackpots that were non-deterministic and progressive also promoted high bet sizes
  • hidden jackpots may be linked to more intense gambling, perhaps because a hidden jackpot suggests a very large prize
  • there was no evidence that mystery jackpots influenced gambling intensity
  • there was no difference in player enjoyment between deterministic and non-deterministic and progressive and nonprogressive jackpots, or with hidden or mystery jackpots
  • linked jackpots were not associated with any significant differences in player behaviour or enjoyment
  • jackpot expiry was effective in limiting player losses, and did not impact on player enjoyment.

The observational component of this project found that:

  • machines with jackpots were associated with a greater spend on the machines across all participants
  • at-risk gamblers were more likely to play on machines with jackpots, and played more intensively on machines with jackpots
  • when primed to think about jackpot wins, at-risk gamblers were more likely than low risk gamblers to select large jackpot machines
  • participants with gambling-related problems spent a longer total time at the venue gambling, but played relatively fewer spins (possibly linked to higher average bet sizes)
  • participants who experienced wins were at greater risk of losing more money overall (possibly due to the intensification of gambling behaviour after a win).

How this research might be useful?

  • The findings from this study have important implications for future EGM policy making in Australia and overseas.
  • The results indicate that jackpot characteristics can encourage risky gambling behaviour.
  • The findings suggest that limiting jackpot size may be a valuable measure to reduce harm from gambling and that jackpot expiry can be used as an effective measure for reducing gambling losses.
  • Moreover, in many cases such alterations need have no negative effect on the consumers enjoyment of the product.

How to cite this research

Matthew Rockloff, Nerilee Hing, Phillip Donaldson, En Li, Matthew Browne, Erika Langham (2014) The impact of electronic gaming machine jackpots on gambling behaviour. Gambling Research Australia. January 2014.

GIRO research update

This summary is included in the March edition of the GIRO research updates.

March 2014 (PDF - 519.2 KB)

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