At older ages, most people are supported by pension systems that provide payments based on prior contributions. An important, but neglected, aspect of inequality in how much people receive in pensions is the number of years they live to receive their pension. We examine inequality in lifetime-accumulated pensions and show the importance of mortality for understanding inequalities in pension payments, and contrast it to inequalities in working-age earnings and yearly pension payments among older adults. In contrast to most previous research on old-age inequality comparing different social groups, we focused on total-population-level inequality. Using Swedish register data covering the retired population born from 1918-1939, we found that lifetime pensions are much more unequal than pre-retirement earnings and yearly pensions. Our findings also show that mortality explains more than 50 percent of the inequality of lifetime pensions within cohorts, and plays an important role in explaining changes in inequality across cohorts (192 percent among men and 44 percent among women). Pension policies can affect lifetime pension inequality, but such effects are limited in magnitude unless they directly affect the number of years of receiving pensions.

The Rescorla and Wagner (1972) model is the first mathematical theory to explain associative learning in the presence of multiple stimuli. Its main theoretical construct is that of associative strength, but this is connected to behavior only loosely. We propose a model in which behavior is described by a collection of Poisson processes, each with a rate proportional to an associative strength. The model predicts that the time between behaviors follows an exponential or hypoexponential distribution. This prediction is supported by two data sets on autoshaped and instrumental behavior in rats.

Mesolithic harpoons are structurally complex weapon points and significant sources of archaeological information. Nonetheless, separating different types of information inherent in harpoon point shapes (e.g., aspects relating to mechanical performance, personal or group craft variation and chronology) using descriptive approaches is difficult. In this study, we employed an exploratory geometric morphometric approach to the analysis of 28 Mesolithic harpoon points, and 144 undated harpoon points from the circum-Baltic Sea area in order to retrieve both functional and spatiotemporal information. By analyzing harpoon structure statistically through (i.) a shape proxy (harpoon silhouette) and (ii.) harpoon sub-structures (barbs), we have been able to reveal information related to both variation in shape convention and functional constraints. Barb shape results revealed statistically significant chronological and geographical groupings with spatiotemporal barb-shape trajectories made visible and objective evaluation of how barb-shape conventions impacted functional variation. In addition, harpoon silhouette shape distributions were shown to have potential as sources for robust artifact classifications in relation to functional constraints and raw-material engagement. These results suggest that morphometric approaches similar to the ones we have employed offer promising ways of addressing specific archaeological questions in the context of harpoon point shapes and, more generally, other complex weapon point forms.

An unusual ski from the Låktatjåhkå / Loktacohkka glacier in Sápmi – Use, wax, 14C and lipid residue analysis: Archaeological skis dated from the Stone Age to today, are not unusual finds in bogs and wetlands. They are found all over Sápmi, from Norway to the Kola peninsula in the Russian federation. Skis are also represented in rock art at different sites in Sápmi and mentioned in written sources; however, skis found at higher altitudes, at glaciers and perennial snow patches, are not as common. In 2018, nine kilometers west of Björkliden, a fragment of a ski was found by the Loktačohkka glacier. The ski fragment was first 14C-dated to the 15th century; however, presence of vax on the fragment presented an interesting problem. A new 14C analysis of the ski fragment, with the wax components removed, now dated the cellulose from the ski to 1645–1916 CE, i.e. the ski could have been used some time from circa 1645 into the first half of the 20th century. This study highlights the importance of regular surveys of melting glaciers and snow patches to retrieve organic material melting out, as well as the importance of investigating what components wood could have been impregnated with.

In the absence of wood, bone, and other organics, one possible candidate for determining the age of a site is the radiocarbon (14C) dating of pottery. In central Europe during the Early Neolithic, pottery was ubiquitous and contained substantial quantities of organic temper. However, attempts at the direct dating of organic inclusions raises a lot of methodological issues, especially when several sources of carbon contribute to the resulting radiocarbon age. Hence an alternative approach to dating of the early pottery is necessary. Here, we present a novel method of bulk separation of organic content from the grass-tempered pottery from Santovka (Slovakia). The procedure is based on the consecutive application of three inorganic acids, dissolving clay, silica content, and low molecular or mobile fractions to separate organic inclusions added to the pottery matrix during the formation of vessels. Radiocarbon dates obtained with this method are coherent and produce the shortest time span compared to other pretreatment methods presented in this study. The paired dates of grass-tempered pots with the 14C age of lipids extracted from the same pots point to a difference of 400–600 14C yr, however they are in line with the site’s chronostratigraphic Bayesian model. Grass-tempered pottery from Santovka (Slovakia) is dated to the first half of the 6th millennium cal BC, making it the earliest pottery north of the Danube. It seems feasible that ceramic containers from Santovka were produced by hunter-gatherers, and pottery predated the arrival of farming in the Carpathian region by a couple of centuries.