Tinbergen Institute

Urban expansion studies typically distinguish three main processes: infill, edge expansion, and outlying development. These general processes do not specifically capture another type of urban expansion: the clumping or coalescing of multiple individual urban areas (patches) into one larger urban agglomeration. This paper develops a new Urban Patch Expansion (UPE) framework that characterises coalescence as an urban expansion process that occurs simultaneously with the three commonly distinguished processes. We characterise two types of coalescence: merging and joining. Merging is defined as the amalgamation of at least two initial patches whose combined area is smaller than the newly added urban area merging them, while joining refers to cases where the total area of the initial urban patches is larger than the newly developed urban area connecting them. In an application of this framework, we analyse urban development in the functional urban area of Bandung (Indonesia) in the period 1975–2015 focussing on the variation in urban development processes along the gradient from the urban centre to the most outward edges of the urban agglomeration. The analysis employs the latest release of the Global Human Settlement Layer (GHSL) that provides a highly detailed rasterised account of urban development since 1975. This new spatial analysis approach enriches our understanding of the spatio-temporal dynamics of urban expansion by providing a more specific account of when and where specific development types prevail. Our research characterises urban development in the Bandung area as a sequence of phases. Outlying development is the most important process in the initial period (1975–1990), highlighting a phase of diffusion. From 1990 coalescence sets in, with joining as the prevalent process in the second period (1990–2000). Infill and edge expansion are steady processes throughout the analysis period, where the latter gradually increases in importance as the urban area continues to grow. Both processes further compact the urban landscape. The final period (2000–2015) shows approximately equal shares of joining, infill and edge expansion. Joining can thus be seen as the first step in the transition from the diffusion to the coalescence stage, whereas the infilling of urban voids and the expansion of city at its edges reflect a more continuous growth process. We observe a similar development sequence over space: edge expansion dominates the zone between 5 and 9 km from the core, joining in the zone up to 17 km and outlying beyond that. The latter process, however, became less important over time. Our approach can be used to compare refined development trajectories in different periods and regions and thus supports our understanding of urban growth. • Novel approach to characterise coalescence along other urban expansion processes. • Identifying both merging and joining of urban patches. • Urban development characterised by subsequent phases of outlying, joining and infill development.

Urban 30 km/h speed limits are increasingly implemented, potentially affecting perceived traffic safety. We assess how exposure to streets transitioning from 50 km/h to 30 km/h affects residents' traffic safety perceptions. We analyzed repeated cross-sectional data from two administrative surveys (N = 4968 and 5146) spanning 2015, 2017, and 2019. Exposure was defined as living within 400m of fifty-six streets across Rotterdam where speed limits reduced from 50 km/h to 30 km/h. Controls lived within 400m of streets undergoing future reductions. Using a difference-in-differences approach, we compared the probability of reporting seven binary outcomes on traffic-related safety, environmental annoyance, and pedestrian and cyclist safety between exposed and control individuals before and after speed limit reductions. We stratified the intervention group in tertiles of intervention street proportion within 400m Euclidian buffers, and additionally cross-sectionally investigated the association between dosage of intervention street density and perceived safety outcomes. No significant differences were observed between residents living near intervention streets and those near control streets. Small, non-significant improvements were found for perceived speeding (−4.6 percentage points (%pt) [95%CI -10.5,1.3]) and aggressive driving (−5.8%pt [95%CI -11.8,0.2]), while bicycle path safety showed a non-significant effect in the opposite direction (6.3%pt [95%CI -0.07,12.6]). The stratified analysis showed a non-significant improvement in the highest exposure tertile of sidewalk safety, but was inconclusive for the other indicators. Dosage findings indicated that a 5% increase in nearby intervention streets was associated with a lower probability of perceived speeding (−1.9%pt [95%CI −3.1,−0.6]), aggressive driving behavior (−1.5%pt [95%CI -3.1,0.04]) and increased bicycle path safety (−1.6%pt [95%CI -3.3,0.04]). Reducing urban speed limits to 30 km/h may have contributed to small, non-significant improvements in perceived traffic safety. The study may have been underpowered to detect statistically significant effects. Future studies should examine intended and unintended effects of traffic safety interventions. • Residents near 30 km/h streets may perceive less speeding and aggressive driving. • Intervention exposure defined as distance to and density of new 30 km/h streets. • Mixed evidence on active transport safety perceptions. • Findings suggest distal consequences of lower speed limits were not affected.

ABSTRACT This paper compares the statistical and economic performance of state‐of‐the‐art high‐frequency (HF) based multivariate volatility models with a simpler, widely used alternative, the Exponentially Weighted Moving Average (EWMA) filter. Using over two decades of 100 U.S. stock returns (2002–2023), we assess model performance through a Global Minimum Variance portfolio optimization exercise, with and without short‐selling restrictions across multiple forecast horizons. We find that the EWMA model cannot consistently be outperformed by more complex HF‐based volatility models at the daily and weekly forecast horizons, even delivering significant utility gains when including transaction costs due to a favorable balance between turnover and ex‐post portfolio volatility. At the monthly horizon, the EWMA remains competitive against most of its competitors. Our findings hold across alternative specifications, including different estimation window lengths, portfolio sizes and smoothing parameter values, emphasizing the continued relevance of parsimonious volatility specifications, such as the EWMA model, in realistic investment settings.

The growing population of individuals with mild cognitive impairment and dementia places increasing demands on home-care systems, while staff shortages and high caregiver workloads underscore the need for assistive technologies. However, research on implementing these technologies in home care practice remains limited. This study examines professional caregivers’ digital onboarding of Tessa, a social robot that supports through verbal reminders. A conceptual digital onboarding probe was evaluated with novice, experienced, and expert users. Findings indicate that the onboarding process improves usability and efficiency by providing intuitive guidance and structured workflows. Additionally, LLMs can translate caregiver-provided goals into actionable robot scripts, though oversight remains essential for quality assurance. The probe and LLM support more effective onboarding and enhance caregiver’s user experience.

This study investigates the relationships between food practices, consumerism, and cultural identity within Dutch and Nepali families. Through semi-structured interviews with 12 families (6 from each cultural context), provides a rich, comparative analysis of how daily food-related activities, shopping, cooking, and eating are shaped by and, in turn, shape cultural values, global market forces, and notions of family cohesion. The primary objectives are to document and analyze daily food practices, explore the cultural meanings attached to food, investigate the influence of globalized consumerism, understand family negotiation strategies, and compare the findings to develop a richer theoretical model. Thematic analysis revealed a stark contrast: Dutch families exhibit a highly pragmatic, efficient, and individualistic ‘Food as Fuel’ paradigm, viewing meals through a lens of logistical management and conscious consumption. In contrast, Nepali families demonstrate a holistic, relational, and ritualistic ‘Food as Love’ paradigm, where food is a core medium for expressing love, maintaining tradition, and reinforcing social bonds. Despite these divergent cultural logics, both groups actively navigate the pressures of global consumerism, with Dutch families leveraging it for convenience and ethical distinction, while Nepali families engage with it as a means of cultural preservation and status negotiation. This study concludes that the kitchen remains a vital, dynamic arena where global and local forces converge, and family identities are continuously cooked, consumed, and redefined.

Abstract. This study presents a statistical time-domain approach for identifying transitions between climate states, referred to as breakpoints, using well-established econometric tools. Our approach offers the advantage of constructing time-domain confidence intervals for the breakpoints, and it includes procedures to determine how many breakpoints are present in the time series. We apply these tools to a 67.1 million-year-long compilation of benthic foraminiferal oxygen isotopes (δ18O), which signify global temperature and ice volume throughout the Cenozoic. This foundational dataset is presented in Westerhold et al. (2020), where the authors use recurrence analysis to identify five breakpoints that define six climate states. Fixing the number of breakpoints to five, our procedure results in breakpoint estimates that closely align with those identified by Westerhold et al. (2020). By allowing the number of breakpoints to vary, we provide statistical justification for more than five breakpoints in the time series. Our method adds to our understanding of Cenozoic climate history in terms of the timing and rate of transitions between climate states and provides a tool for robustly assessing breakpoints in many other paleoclimate time series.