1\section{Geographic heterogeneity}2\label{sec:geography}34Figure~\ref{fig:map} maps the coverage of the stage-one included records and of the extracted studies, and Table~\ref{tab:geography}5lists the countries contributing the most records and estimates. Coverage is broad in records (\nCountriesStageOne{} countries at6stage one) and narrower in extracted full texts (\nCountriesExtracted{} countries), because open-access availability is itself7unequal across publication venues and regions. Figure~\ref{fig:geo} shows the distribution of harmonised estimates by continent8for the six most-studied characteristic--family combinations. The living-area elasticity is centred between 0.5 and 0.8 on9every continent with at least five studies; the bedroom semi-elasticity is close to zero in North America, where living area is10almost always controlled, and larger in Asia and Europe, where room counts more often proxy for size; the age semi-elasticity is11negative everywhere with a wider dispersion in Asia, where samples mix new-build and resale apartments; and the premium of a12detached dwelling type varies from negative to large positive values within Europe, which reflects the diversity of reference13categories rather than a geographic law. The moderator analysis of Section~\ref{sec:methodological} tests the non-US indicator14formally: it is significant in \nSigNonus{} of \nTestedNonus{} models, raising the living-area semi-elasticity outside the United15States, and insignificant elsewhere. The honest summary of RQ3 is that geography matters through the composition of studies16(property types, specifications, units) more than through a detectable continental shift in implicit prices once those are17controlled, with the important caveat that Africa, South America and Oceania contribute too few studies for any contrast to be18powered.1920\begin{figure}[H]21\centering22\includegraphics[width=\textwidth]{fig03_world_coverage.pdf}23\caption{Geographic coverage: stage-one included hedonic records (country from title and abstract) and extracted studies.}24\label{fig:map}25\end{figure}2627\begin{table}[H]28\centering29\caption{Geographic distribution of the evidence (countries with the most stage-one included records)}30\label{tab:geography}31\small32\resizebox{0.8\textwidth}{!}{\input{tables/tab02_geography}}33\end{table}3435\begin{figure}[H]36\centering37\includegraphics[width=\textwidth]{fig08_geographic_heterogeneity.pdf}38\caption{Distribution of harmonised estimates by continent for the six most-studied characteristic--family combinations39(boxes: interquartile range; line: median; whiskers: 1.5 IQR; $k$ = studies).}40\label{fig:geo}41\end{figure}42