The Portuguese labour market has stabilised after the 2010–2013 sovereign debt crisis, which pushed unemployment to a historic 18.5%. By 2025, the rate of unemployment has exhibited low-record levels reaching 5.9%. Long-term unemployment has declined, and the female employment rate reached historical values. Yet, several structural imbalances persist. Productivity levels remain low compared to European peers, and wages continue to struggle to keep pace with the cost of living.

How do minimum wage policies interact with labour tax evasion? In many transition economies, two features stand out: a large spike in the wage distribution at the minimum wage and widespread use of “envelope wages”—undeclared cash paid in addition to official earnings. This spike can be explained by the over-representation of tax-evading employers among minimum wage payers. In such a context, raising the minimum wage may serve as an enforcement tool by compelling evading firms to convert part of the undeclared pay into formal wages in order to comply with the legal minimum.

While Mexico has improved the education of its labor force, maintained a stable macroeconomic environment, and been friendly to international trade, its labor market still faces many challenges. In particular, Mexico has difficulty creating high-paying jobs: the share of informal employment has remained stagnant for the last 20 years, and, by 2025, remains above 50%. These problems are particularly poignant in southern Mexico.

It is common practice to incorporate additional covariates in empirical economics. In the context of regression discontinuity (RD) designs, covariate adjustment plays multiple roles, making it essential to understand its impact on analysis and conclusions. Typically implemented via local least squares regressions, covariate adjustment can serve three main distinct purposes: (i) improving the efficiency of RD average causal effect estimators, (ii) learning about heterogeneous RD policy effects, and (iii) changing the RD parameter of interest.