The relative age effect associated with cut-off dates for hockey eligibility has been an ongoing debate in certain academic circles and in the popular media. The effect is primarily found in Canadian Major Junior Hockey, where a disproportionate share of birthdays fall in the first three months of the year. But when the National Hockey League rosters of Canadian-born players are examined, the pattern is less pronounced. Using publically available data of hockey players from 2000–2009, we find that the relative age effect, as described by Nolan and Howell (2010) and Gladwell (2008), is moderate for the average Canadian National Hockey League player and reverses when examining the most elite professional players (i.e. All-Star and Olympic Team rosters). We also find that the average career duration is longer for players born later in the year. In sum, there is a surprising ‘relative age effect reversal’ that occurs from the junior leagues to the most elite level of hockey play. This supports an ‘underdog’ hypothesis, where the relatively younger players are thought to benefit by more competitive play with their older counterparts.

One of the most consistent patterns in the social sciences is the relationship between sibship size and educational outcomes: those with fewer siblings outperform those with many. The resource dilution (RD) model emphasizes the increasing division of parental resources within the nuclear family as the number of children grows, yet it fails to account for instances when the relationship between sibship size and education is often weak or even positive. To reconcile, we introduce a conditional resource dilution (CRD) model to acknowledge that nonparental investments might aid in children’s development and condition the effect of siblings. We revisit the General Social Surveys (1972–2010) and find support for a CRD approach: the relationship between sibship size and educational attainment has declined during the first half of the twentieth century, and this relationship varies across religious groups. Findings suggest that state and community resources can offset the impact of resource dilution—a more sociological interpretation of sibship size patterns than that of the traditional RD model.

While the use of inferential statistics is a nearly universal practice in the social sciences, there are instances where its application is unnecessary and potentially misleading. This is true for a portion of research using administrative data in educational research in the United States. Surveying all research articles using administrative data published in Educational Researcher and American Educational Research Journal between 2011 and 2013, we find that over half use inferential techniques to help interpret results despite the use of population data. To the extent that these practices and findings are replicated and interpreted in the United States and elsewhere, this can lead to the undervaluing of potentially meaningful patterns and trends.