Essays on the Socio-Economics of Recent Demographic Change and Ancient Technology Diffusion

In Chapter 1, we study an under-explored implication of population ageing, i.e., its effect on country-level environmental outcomes and on individual-level environmental attitudes. In doing so, we propose a novel classification of country-level environmental outcomes, namely action-requiring and nature-concerning. The borderline between these two categories lies in the level of civic engagement required to fulfil them. Using panel data from a broad set of countries (1995–2018), we find that population ageing is linked to improvements in environmental outcomes that require minimal civic engagement, while it shows no clear association with outcomes that depend on active participation. Analysis of individual-level survey data (2005–2016) further suggests that ageing societies tend to exhibit lower levels of environmental engagement, without affecting individuals’ underlying environmental concern. In Chapter 2, we investigate how population ageing affects economic growth by altering the composition of government expenditure. We develop and test a political economy model in which an ageing population shifts the preferences of the median voter, leading to increased spending on the elderly at the expense of investment in growth-enhancing areas, thereby reducing growth. Using OECD data from 2007–2018 and both OLS and IV regression analyses, we find strong evidence that population ageing raises spending on elderly and healthcare services, while having no significant effect on productive expenditure categories such as education and infrastructure. Extending the analysis to a broader sample of countries with GMM estimation, we confirm that elderly spending, proxied by healthcare expenditure, has a negative impact on economic growth. In Chapter 3, I study the emergence and diffusion of production techniques using archaeological artefacts from the British Museum. I construct a dataset of over 800,000 artefacts containing geographic and chronological information. I develop a method to identify the techniques employed in their production using large-language and vision-language models. Using these data, I reconstruct the spatial and temporal distribution of the earliest adopters of production techniques, referred to as pioneering sites, and examine how distance from these points of origin relates to the delay in the adoption of techniques. Overall, the results show that sites located closer to pioneering sites tend to adopt production techniques earlier.