https://hdl.handle.net/2072/478940 2026-03-28T15:16:19Z 2026-03-28T15:16:19Z Gracia, Eduard https://hdl.handle.net/2445/228551 2026-03-28T09:26:07Z 2026-03-27T08:48:58Z

Follow the median: revisiting bubbles and cycles Gracia, Eduard Under very general conditions, the best predictor of any random variable’s observed time series is not its mean but its median. Hence, if we aim to model a variable with a skewed (a.k.a. asymmetric) probability distribution, so mean and median diverge, it is the model’s predicted median path that must be compared to that variable’s observed time series. Thus e.g. rational economic agents base their decisions on their target variables’ expected (a.k.a. mean) paths, which must as a result follow certain rules (mainly no arbitrage); but, if those variables are skewedly distributed, irrational-looking observations may not reflect irrationality, for the median is not subject to the rules rationality imposes on the mean. Yet economic models rarely pose this hypothesis and, when they do, their skewness assumptions often present major theoretical and/or empirical drawbacks. This paper proposes instead to assume normally distributed (hence symmetric) random perturbations and then rely on economics’ standard nonlinear assumptions (e.g. diminishing returns, decreasing marginal utility, etc.) to skew relevant variables’ distributions endogenously. (.../...)

2026-03-27T08:48:58Z Benati, Giacomo Lozano, Sergi https://hdl.handle.net/2445/228545 2026-03-28T09:25:52Z 2026-03-27T07:24:44Z

The Network Structure of the Urban Revolution Benati, Giacomo; Lozano, Sergi Although long-distance interaction dates back to Prehistory, the scale and complexity of exchange during the Urban Revolution are unparalleled. How did early urban societies organize transcontinental trade without modern transportation, financial systems, or institutional infrastructures? To answer this, we formally analyze the Uruk Expansion in Chalcolithic Mesopotamia (~4000–3000 BCE), arguably the first episode of “globalization” in human history. Using network analysis on a new dataset of over 1,700 settlements and routes, we show that Uruk’s early river-based supply chains evolved through diaspora-driven bridging ties that generated small-world network structures, fostering integration and system-wide connectivity. This transformation—from dendritic to integrated networks—challenges dependency-based explanations and instead supports a market formation model of early urban exchange.

2026-03-27T07:24:44Z Jelnov, Artyom Senkov, Maxim https://hdl.handle.net/2445/228549 2026-03-27T23:37:19Z 2026-03-27T08:22:58Z

Democratic backsliding in times of crisis Jelnov, Artyom; Senkov, Maxim In a political-agency model, an incumbent can initiate a restrictive policy in response to a crisis state of the world. Both the opposition and the citizen value the incumbent's policy matching the state; however, they are uncertain about the incumbent's true motives. If the incumbent is of the dictatorial type, a restrictive policy that is not protested by both the opposition and the citizen leads to the start of authoritarian rule. We show that when the incumbent is relatively unlikely to be dictatorial, the presence of radical opposition, protesting the restrictive policy regardless circumstances, can reduce voter welfare: it eliminates the efficient state-matching equilibrium, since the opposition never fully reveals dictatorial incumbents. Conversely, when the incumbent is relatively likely to be dictatorial, a high probability of radical opposition can increase voter welfare by deterring the dictatorial type from implementing the restrictive policy.

2026-03-27T08:22:58Z Martínez Galarraga, Julio Prat Sabartés, Marc https://hdl.handle.net/2445/225685 2026-01-20T01:50:06Z 2026-01-19T07:59:22Z

The expansion of primary education in an industrialising economy: Catalonia in the age of mass schooling (1860-1930) Martínez Galarraga, Julio; Prat Sabartés, Marc This paper studies the main patterns and trends observed in primary education in Catalonia between 1860 and 1930. The information gathered from official education statistics makes it possible to track several primary education variables over time, including pupils, schools, teachers and public spending, at 10-year intervals, broken down by public and private schooling and by gender. This study, which is primarily descriptive in nature, provides new quantitative evidence that highlights the difficulties faced by the public provision of primary education in achieving progress in Catalonia during those years, the significant expansion of private education, the disparities between rural and urban areas (where demographic pressure on the education system was greater), and the advances and setbacks in achieving gender equality. Together, the findings contribute to a deeper understanding of how a society—in this case, Catalonia—coped with the challenge posed by the spread of mass schooling during the early stages of industrialisation, within a backward institutional framework typical of Southern Europe’s peripheral regions.

2026-01-19T07:59:22Z