Agenda 2030 suggests a set of indicators chosen by expert groups to monitor the achievement of the SDG’s targets, on the basis of in-depth analyses and reviews of the scientific literature. In order to meet the objective of this contribution and to cope with the lack of up-to-date and reliable data, sentinel proxy indicators were identified in order to compare base and post Russia-Ukraine war scenarios.

In order to depict the sustainability path of Mediterranean coastal cities through the lens of urban development we compared the following indicators (source: NUMBEO) between 2021 and 2022:

– The Pollution Index is based on several indicators such as air pollution (concentration of PM2.5 and PM10), water pollution, accessibility, noise and light pollution, green and park quality, and waste disposal management.

– The Crime Index is an estimation of overall level of crime based on the number of crimes committed and the perception of danger of contributors to the website. It goes hand in hand with the Safety Index which is, instead, an estimation of the overall level of safety.

The selected indicators are not adequate to describe the sustainability pattern of the selected cities but given their temporal variability they can quantify appreciably the possible effects of the Russian-Ukrainian war on building sustainable cities and society.

The current geo-political crisis of the Russian-Ukrainian conflict and its economic consequences have seriously jeopardized the ability to tackle the daunting global challenge of sustainability. The ongoing war has led to a spike in energy and basic commodities prices in Europe and beyond, contributing, amongst other things, to a global supply chain crisis, to unsustainable production in the sectors hardest hit, and resulting in runaway inflation worldwide [Del Lo et al. 2022; Kuzemko et al. ¶{p. 337}2022; Liadze et al. 2022]. However, the paradigm of sustainable development takes the form of an urgent and decisive response to be implemented in order to ensure economic recovery and strengthen the resilience of economies.

Given the rapid and growing pace of urbanization on a global basis [1] , and the social, environmental and economic repercussions of this phenomenon [2] , investigation of progress towards sustainable development at urban level emerges as an important topic for researchers and policy makers. In this chapter we seek to explore to what extent the current economic shock resulting from the Russian and Ukrainian conflict may affect the chances of Mediterranean cities succeeding on their sustainable development course, comparing their socio-economic conditions before and after the conflict. As part of Agenda 2030 signed by the member countries of the United Nations, Sustainable Development Goal (SDG) 11 aims to build «Sustainable cities and communities». A more equitable urban environment can make a decisive contribution to the transition process towards sustainability. Ensuring universal access to basic services, a more «affordable» life for all citizens and reducing inequalities are essential tasks for making cities more inclusive and sustainable. Citizens can act as agents of structural change towards sustainable development, but only if suitable pre-conditions exist to do so. For this purpose, we embed the environmental analysis within the study of the social and welfare dimension, adopting an integrated approach, in order to assess the overall advancement of Mediterranean cities towards sustainable urban development. Empirical research from urban economics has found that, besides environmental conditions, such as the level of pollution, that greatly influence human health and therefore the quality of life, other factors, like the local purchasing power, cost of living and level of rent have a significant impact on the quality of life of cities, which can be recognized as a general ¶{p. 338}expression of reasonable and good living conditions existing in locations [Ali, Audi and Al-Masri 2022] [3] .

A society that is less inclusive in terms of social participation and welfare can hinder the achievement of environmental sustainability goals: low-income householders have less access to basic necessities such as health care, alternative water sources, or housing options, which are useful tools for reducing or avoiding the impact of exposure to environmental harms [Maguire and Sheriff 2011].

The target 11.1 states that, by 2030, access for all to adequate, safe and affordable housing and basic services and upgrade slums’ must be ensured. The lack of affordable housing options and access to essential services for low-income households could prevent cities undertaking a more sustainable pattern [Smets and Van Lindert 2016]. It is considered a priority issue to establish housing policies targeting the most vulnerable segments of the population at the bottom of the income scale [UN 2022].

Although the price of renting accommodation is considered one of the most important indicators for determining the living quality of citizens [Shapiro et al. 2006; Aragonés, Amérigo and Pérez-López 2017], average wage, cost of utilities and other variables should also be taken into account to properly assess citizens’ quality of life.

According to Albouy and Lue [2015], local wage levels, housing costs (or price of renting) and commuting costs, which vary substantially between and within cities, affect householders’ ability to lead an affordable life and hence the average local disposable income. Wages play a fundamental role in ensuring a better quality of work-life and promoting social welfare: a wage level able to guarantee access to affordable primary and basic amenities means that work can act as a driving element of a sustainable livelihood and collective well-being for citizens.

Mutual interactions between wages and quality of (work) life fuel welfare and sustainability of cities: higher average wages and a better quality of work allows not only productivity and ¶{p. 339}efficiency improvements in the local labour market and individual welfare gains for workers, but also a socially «healthier» local environment [Carr et al. 2018] leading to sustainable cities [Gargiulo and De Ciutiis 2010].

Based on this idea, we can calculate some useful indicators to proxy cost-of-living affordability as a dimension of quality of life in the cities. We establish the apartment rent to wage ratio as a measure of housing affordability, comparing the monthly average rental costs with the average monthly net salary for each city [4] .

Rent costs are considered a fuller measure of the «urban costs» faced by households [Albouy and Lue 2015]: if the rental cost is very high compared to the average wage, it means that those who receive lower wages would have less money available to spend on other primary needs such as food, health care and transportation [School Harvard Kennedy 2019]. For this reason, we extend the apartment renting price to wage ratio by adding the cost of different basic amenities, attempting to capture the cost of living. The concept of a living wage has its roots in the origins of economic thought, and it has been subject of regulation by state and supra-state legislation in recent years. It can be basically defined as the wage that is supposed to provide workers’ basic needs, such as food, housing and clothes, and services, such as transportation, but also the possibility to participate in cultural and social life [Schulten and Muller 2019].

Affordable public transportation is one of the important issues in the living wage also tackled by SDG target 11.2, concerning the provision of safe, affordable and sustainable transport systems by 2030. In fact, «only about half the world’s city dwellers have convenient access to public transportation» [UN 2022].

Given that this conflict has seriously affected the fuel prices of the economies under study [Kalogiannidis et al. 2022], it is necessary to include the cost of gasoline (per litre), adjusted for inflation, in our analysis to evaluate the impact of this crisis on transport price trends, that can affect the well-being and sustainability of cities. However, the fuel price will be analysed ¶{p. 340}separately and not be included as part of the living wage since (1) there is no estimation of the average km that people usually drive and (2) it interacts with other variables in the living wage.

Additionally, good quality public transportation is more important for long-run sustainability.

In addition to the indicators created to capture the effects of the Russian-Ukrainian conflict on urban sustainability, we would like to see whether national regulations on the minimum wage can help to control the effects of conflict. In fact, according to Standing [2011] and Carr et al.[2018], jobs can also be unsustainable however, for instance if a legal minimum wage falls below the basic cost-of-living. The provision of minimum wages by force of law should fulfil its designated role in allowing full-time workers to afford the basic cost of living [Dube and Lindner 2021] and to enjoy an adequate, minimum standard of living [Schulten and Muller 2019], carrying out the task of «protecting» above all the lowest wage earners and reducing wage inequality. For this reason, we include the minimum and average wage ratio, the so-called Kaitz index, as a measure which is able to capture the effects of introducing a minimum wage and differences in wage dispersion across our sample cities. We take into account the state-level minimum wages of each city. In this way, we can evaluate whether the minimum wage established at national level corresponds to the desirable one, in cities that have, for example, higher living costs.

– Rental house affordability is the price of renting a one-bedroom apartment relative to the average monthly net salary (after tax). Since data about household income are not available and family structure can be different by city, we focus on the affordability of one-room apartments with one salary. The average price of renting a one-bedroom apartment is calculated as the mean of the price of renting an apartment in the city centre and the price of renting outside the centre.

– Living costs to the monthly wage ratio is the sum of utilities expenditure, including the monthly local transport pass for, as well as the price of renting relative to the monthly wage.