sustainability Article Population Dynamics and Agglomeration Factors: A Non-Linear Threshold Estimation of Density Effects Mariateresa Ciommi 1, Gianluca Egidi 2, Rosanna Salvia 3 , Sirio Cividino 4, Kostas Rontos 5 and Luca Salvati 6,7,* 1 Department of Economic and Social Science, Polytechnic University of Marche, Piazza Martelli 8, I-60121 Ancona, Italy;
[email protected] 2 Department of Agricultural and Forestry Sciences (DAFNE), Tuscia University, Via San Camillo de Lellis, I-01100 Viterbo, Italy;
[email protected] 3 Department of Mathematics, Computer Science and Economics, University of Basilicata, Viale dell’Ateneo Lucano, I-85100 Potenza, Italy;
[email protected] 4 Department of Agriculture, University of Udine, Via del Cotonificio 114, I-33100 Udine, Italy;
[email protected] 5 Department of Sociology, School of Social Sciences, University of the Aegean, EL-81100 Mytilene, Greece;
[email protected] 6 Department of Economics and Law, University of Macerata, Via Armaroli 43, I-62100 Macerata, Italy 7 Global Change Research Institute of the Czech Academy of Sciences, Lipová 9, CZ-37005 Ceskˇ é Budˇejovice, Czech Republic * Correspondence:
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[email protected] Received: 14 February 2020; Accepted: 11 March 2020; Published: 13 March 2020 Abstract: Although Southern Europe is relatively homogeneous in terms of settlement characteristics and urban dynamics, spatial heterogeneity in its population distribution is still high, and differences across regions outline specific demographic patterns that require in-depth investigation. In such contexts, density-dependent mechanisms of population growth are a key factor regulating socio-demographic dynamics at various spatial levels. Results of a spatio-temporal analysis of the distribution of the resident population in Greece contributes to identifying latent (density-dependent) processes of metropolitan growth over a sufficiently long time interval (1961-2011).