During the 2008 economic crisis, labour market inactivity, unemployment and work informality in Serbia rose substantially, triggering a salient increase in Gini-measured inequality (by 4.3 pp), while income tax progressivity remained very low. Using the micro-simulation and utility function estimation techniques on 2007 and 2012 household survey data for Serbia, we compare the social welfare effects of a hypothetical shift from flat to progressive taxation, before and after the crisis. We find that a shift from flat to progressive tax and the consequent behavioural response lead to a reduction in inequality, a rise in total labour supply and an increase in the overall social welfare in both years. Although the decrease in inequality is higher in 2012, the overall welfare effects are slightly larger in 2007, due to the stronger labour supply response and the stronger disutility of work found in the latter year. This may suggest that a rise in inequality does not per se create a stronger case for progressive taxation, as the welfare effects are considerably driven by the structure of income-leisure preferences.

中文翻译：

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不平等加剧下累进所得税的社会福利效应

在2008年的经济危机期间，塞尔维亚的劳动力市场不活跃，失业和工作非正式性大幅度上升，这触发了以基尼衡量的不平等现象的明显增加（4.3 pp），而所得税的累进率仍然很低。使用2007年和2012年塞尔维亚家庭调查数据的微观模拟和效用函数估计技术，我们比较了危机前后假设从固定税制向累进税制转变的社会福利效应。我们发现，在过去的两年中，从统一税改为累进税，以及随之而来的行为反应，导致了不平等的减少，总劳动力供应的增加以及总体社会福利的增加。尽管不平等的减少在2012年有所增加，但2007年的整体福利影响略大，由于对劳动力供应的反应更加强烈，并且在下一年发现了对工作的更大的无用功。这可能表明，不平等现象的增加本身并不能为累进税制提供更强有力的理由，因为福利效应在很大程度上受到收入休闲偏好结构的驱动。