We investigate the manual selection of numbers by lottery participants,with a database consisting of over 800 million selections from 118 consecutive draws of the national lottery in Israel. Our findings replicate results from prior research and introduce novel discoveries.(1) Preference for, and avoidance of, specific numbers 1 through 37 are consistent throughout all the drawings. Strong, but differing preferences are observed in the selection of the “power” number ranging from 1 to 7. (2) The number of guesses entered per draw correlates with the size of the prize, with each additional million in prize money generating 33,000 additional manual guesses. (3) Number preferences are strongly influenced by their location on the form. Numbers in the first of the four horizontal rows are consistently the most popular, while numbers in the fourth rows are consistently unpopular. (4) As the number of guesses increases, popularly chosen numbers tend to become slightly less popular, while unpopular numbers tend to become less unpopular.

Theoretical equivalence exists among various auction mechanisms, specifically the Second-Price-Auction (SPA), a competitive environment, and the BDM mechanism, a non-competitive environment. Yet, empirical studies suggest that behavior in these mechanisms may diverge. Our experimental study examines the WTP and the WTA of individuals by analyzing buying and selling bidding patterns both for a physical product (mugs) and for two types of lotteries (regular lotteries and extreme lotteries) in these two auctions mechanism: SPA and BDM. We found that the WTP in the SPA is higher than the WTP in the BDM for mugs and for regular lotteries, while the mechanisms do not differ significantly for extreme lotteries. In addition, the WTA in the SPA is lower than in the BDM for regular lotteries only. These results indicate that the WTP and WTA, as well as the WTA-WTP gap, tend to differ in the SPA and in the BDM as a result of the interaction between the competitiveness effect and other psychological effects on bidding patterns for riskless and risky assets. In addition, the current study suggests that the competitiveness effect depends not only on the type of mechanism (SPA), but also on the type of item (physical assets or lotteries) and the type of lottery. In addition, the influence of the competitiveness effect may vary between buying and selling positions.

Unbiased lotteries seem the least unfair and simplest procedures to allocate scarce indivisible resources to those with equal claims. But, when lotteries are repeated, it is not immediately obvious whether prior winners should be included or excluded. As in design questions surrounding single-shot lotteries, considerations of self-interest and distributive social preferences may interact. We investigate preferences for allowing participation of earlier winners in sequential lotteries. We found a strong preference for exclusion, both in settings where subjects were involved, and those where they were not. Subjects who answered questions about both settings did not differ in their tendency to prefer exclusion. Stated rationales significantly predicted choice but did not predict switching of choices between the two settings.

Although the priority heuristic (PH) is conceived as a cognitive-process model, some of its critical process assumptions remain to be tested. The PH makes very strong ordinal and quantitative assumptions about the strictly sequential, non-compensatory use of three cues in choices between lotteries: (1) the difference between worst outcomes, (2) the difference in worst-case probabilities, and (3) the best outcome that can be obtained. These aspects were manipulated orthogonally in the present experiment. No support was found for the PH. Although the main effect of the primary worst-outcome manipulation was significant, it came along with other effects that the PH excludes. A strong effect of the secondary manipulation of worst-outcome probabilities was not confined to small differences in worst-outcomes; it was actually stronger for large worst-outcome differences. Overall winning probabilities that the PH ignores exerted a systematic influence. The overall rate of choices correctly predicted by the PH was close to chance, although high inter-judge agreement reflected systematic responding. These findings raise fundamental questions about the theoretical status of heuristics as fixed modules.

The transitivity axiom is common to nearly all descriptive and normative utility theories of choice under risk. Contrary to both intuition and common assumption, the little-known ’Steinhaus-Trybula paradox’ shows the relation ’stochastically greater than’ will not always be transitive, in contradiction of Weak Stochastic Transitivity. We bespoke-design pairs of lotteries inspired by the paradox, over which individual preferences might cycle. We run an experiment to look for evidence of cycles, and violations of expansion/contraction consistency between choice sets. Even after considering possible stochastic but transitive explanations, we show that cycles can be the modal preference pattern over these simple lotteries, and we find systematic violations of expansion/contraction consistency.

In this paper, we examined two pairs of datasets from selected Nigerian lottery games to determine players’ number preferences. Data explorations were conducted in the first pair of datasets to identify patterns in players’ choices of lottery numbers. The question whether players preferred number combinations that are well-spread out regardless of their true theoretical probabilities was examined in the second pair. In the first pair of datasets, we find that most players have a preference for small numbers especially 1 and 9. They also prefer numbers with repeated digits and tend to avoid multiples of 7 and numbers containing 7 (except 7 and 77). The most popular numbers are 90 and 1. In the second pair of the datasets, more than 50% of the players preferred selecting well-spread out number combinations than expected by chance.

We explore people’s preferences for numbers in large proprietary data sets from two different lottery games. We find that choice is far from uniform, and exhibits some familiar and some new tendencies and biases. Players favor personally meaningful and situationally available numbers, and are attracted towards numbers in the center of the choice form. Frequent players avoid winning numbers from recent draws, whereas infrequent players chase these. Combinations of numbers are formed with an eye for aesthetics, and players tend to spread their numbers relatively evenly across the possible range.

Overcoming vaccine hesitancy is critical to containing the COVID-19 pandemic in the United States. To increase vaccination rates, the State of Ohio launched a million dollar lottery in May 2021. Following a pre-registered analysis, we estimate the effects of Ohio’s lottery program Vax-a-Million on COVID-19 vaccination rates by comparing it to a “synthetic control” composed of eight other states. We find a statistically insignificant 1.3% decrease in the full vaccination rate in Ohio at the end of the lottery period. We investigate the robustness of our conclusion to model specifications through a multiverse analysis of 216 possible models, including longer time periods and alternative vaccination measures. The majority (88%) find small negative effects in line with the results of our pre-registered model. While our results are most consistent with a decrease in vaccination rate, they do not allow a firm conclusion on whether the lottery increased or decreased vaccine uptake.

When it is most fair for a claimant to receive a particular chance of benefiting (e.g. 50%) but they instead receive a different chance of benefiting (e.g. 40%), this lower chance is not ideally fair. I specify the often-overlooked type of individual unfairness evident in differences of this kind and argue for four intuitively supported criteria that a measure of this unfairness must meet. I defend the Asymmetrical Proportional View, which meets these criteria and is a measure of how individually unfair any particular difference of this kind is. Finally I conclude with the View's implications for theories of distributive fairness.

The case of a lady who developed a major depressive illness with secondary pathological gambling is described. The gambling was manifest by uncontrolled purchasing of lottery tickets. The inter-relationship between affective disorder and pathological gambling and the effect, if any, of lotteries on pathological gambling is discussed.