There is some older literature from the 70’ and 80’ which we will not cover and concentrate on the more recent publications.4 The incidence of transit subsidies has been studied for urban areas in Spain by Asensio, et al. (2003). They estimate a transit expenditure equation and then simulate the impact of subsidies on this expenditure for different household incomes. They find that urban transport subsidies are progressive, in the sense that the subsidy received as a percentage of income decreases with income. They also calculate the difference in the Gini coefficient with and without transit subsidies and find that these benefits improve the income distribution, but the change is very modest owing to the relatively small share of transit within total household expenditure.
Bueno Cadena, et al. (2016) used the 2004 Madrid mobility survey to estimate the distributive incidence of transit subsidies by estimating travel card use by neighborhood. They find that travel card use is higher in poorer neighborhoods suggesting a progressive incidence of benefits.
Börjesson, et al. (2020) study the incidence of transit subsidies in Stockholm, Sweden. The novelty of their approach is that they estimate subsidies by trip link considering differences in costs and loads by mode and service. They then impute the subsidy received by passengers according to the fare paid and the cost of the different links used in their trips. This granular approach effectively identifies cross subsidies among transit users and thus gives a more detailed picture of the distributional impact of benefits. They then use a Concentration Curve index to estimate the incidence of these transit subsidies and conclude that they are mildly progressive, but perhaps less than would be expected ex-ante. They also analyze the incidence by different social groups and simulate the distributive effects of different fare structures.5
Silver, et al. (2023) study the distributive incidence of the 2019 fare reform In Lisbon, Portugal, that simplified the fare structure from over 300 passes to just one pass with a flat rate. They use a generalized cost approach to analyze the incidence of this reform by demographic groups. They also use the Palma Ratio and conclude that the reform reduced inequality; the transit expenditure reduction of the 40% lowest income individuals was larger than the expenditure reduction for the highest 10% of income.
Studies for developing countries are few. Interestingly, available research often suggests different incidence results to those reported in the above publications for developed countries. For example, Flynn (2007) shows that transport subsidies in Mexico City are not as pro-poor as is commonly believed. The majority of the poor do not benefit from the metro, public bus, trolley, and light railway subsidies that form the bulk of transport subsidies in that city. Bhattacharya and Cropper (2007) find similar results for bus and rail subsidies in Mumbai, India. Gómez-Lobo (2009) studies the distributive impact of a series of transport related taxes and subsidies in Santiago, Chile, including bus and metro fares. The novelty of this last study is that in some cases subsidies are funded through cross subsidies and thus the incidence of revenues is also included in the analysis. Although subsidies are mildly progressive, using cross-subsidies to fund student concessionary fares reduces the positive impact of this benefit. Vecchio, et al. (2024), also for Santiago, study the fairness of different transit policies, including fare subsidies, but only for a specific demographic group (the elderly).
Another literature deals with the transport behavior or labor market outcomes induced by transit subsidies. For example, Brough, et al. (2022) for a voucher experiment in Kings County, Washington, Guzman, et al. (2023) for a randomized controlled experiment with transit voucher and Guzman and Hessel (2022) for a means-tested transit subsidy, both in Bogotá, Colombia, Franklin (2017) for a randomized experiment with transit subsidies for unemployed youth in urban Ethiopia, Hall, et al. (2021) for an employer paid transit subsidy in Vancouver, Canada, and Bull, et al. (2020) on a randomized control trial with free transit fares in Santiago, Chile. Special mention should be given to Moreno-Monroy and Posada (2018) who study the effects of different types of transit subsidies on informality using a linear city urban economic model. They find that subsidies targeted to informal workers do not increase welfare or reduce informality rates. Since all these papers deal only tangentially with subsidy incidence, we will not discuss them further.
For Brazil we have been unable to find any published research analyzing the Vale Transporte scheme. Herszenhut, et al (2022) examine the impact of including monetary costs in access inequality measures in Rio de Janeiro. However, they do not examine the incidence of transit subsidies. Closer to the objective of the present paper is Proque, et al. (2022) who use a dynamic general equilibrium model to simulate the economic and distributive effects of eliminating fuel taxes or using fuel tax revenues to finance lower bus fares in Brazil. Proque, et al. (2023) use a similar model to study the effects of urban transport subsidies. However, in both cases the analysis is very aggregate. For example, Proque, et al. (2023) use five representative households, annual operational subsidies for public transport at the national level and do not consider the large informal sector of the Brazilian economy. The Vale Transporte scheme is not mentioned in these papers.
From a methodological perspective, recent studies have used a Concentration Curve index (CI) approach (Gómez-Lobo, 2009; Börjesson, et al., 2020; Karner, et al., 2024) that is also common in the study of public utility subsidies (Palma, et al., 2018; Gómez-Lobo, et al. 2023).6 This consists of graphing a Lorenz curve of the incidence of the subsidy as shown in Fig. 1. Let I represent income and F(I) is the cumulative distribution function of income. Likewise, define S(I) as the cumulative distribution of benefits, that is, the proportion of total benefits received by individuals or households with incomes I or less. The Lorenz curve is then the graph of F(I) and S(I). If we define A as the area under the Lorenz curve, then the CI (Kakwani, 1977) is equal to \(CI=1-2\bullet A\) and is bounded between (-1,1).7 If the Lorenz curve is below the 45-degree line, the index is positive and indicates a regressive incidence of the benefit since the proportion of total benefits accruing to poorer families is below their proportion in the population. A negative value indicates a progressive targeting of the benefit.
The CI of Kakwani (1977) is similar to the Suits (1977) index, however, this last index is calculated from a Lorenz curve where the horizontal axis measures the proportion of total income accumulated by individuals or households, rather than their proportion in the population. As explained in Börjesson, et al. (2020), in this case the Lorenz curve will coincide with the 45-degree line if benefits are proportional to income, indicating that benefits over income is the same for all individuals or households. In contrast, in the Kakwani (1977) approach the 45-degree line represents a scenario where all individuals or households receive the same absolute amount of the benefit. The Suits (1977) approach would be relevant if one wishes to examine the progressiveness of the subsidy in a vertical equity sense. If everyone receives the same absolute value of benefits it would be a progressive subsidy according to the Suits (1977) index, since lower-income individuals receive a higher proportion of their income in benefits, while it would be a neutral subsidy under the Kakwani (1977) index.
Since our interest lies in the targeting properties of the Vale Transporte subsidy, we will use the Kakwani (1977) Concentration Curve index. We want to explore how well this benefit targets low-income individuals and it is in this sense that we will label the subsidy progressive or regressive. For clarity we call this the targeting incidence of the subsidy to distinguish it from the distributive incidence in a vertical equity sense.
One potential problem with the CI noted by Karner, et al. (2024) is that it is influenced by the incidence of benefits along the whole range of the income distribution with equal weight given to low and high-income beneficiaries.8 One alternative to overcome this problem would be to follow Karner, et al. (2024) and use the “Corrected Concentration Index” of Erreygers (2009) whereby weights are inversely proportional to income rankings. Another alternative would be to use the Palma Index used by some researchers and which in the present context implies comparing the average subsidy received by the 10% richest individuals to the average subsidy received by the 40% lowest income individuals. However, we prefer to use the Ω index originally used by Coady et al. (2004) and Komives, et al. (2005). This index compares the average benefit received by a predefined target population (e.g. the poor) to the average benefit received by all beneficiaries and is defined as follows:
$${\Omega }=\frac{\frac{{S}_{P}}{{S}_{T}}}{\frac{P}{T}}$$
Where P is the number of individuals in the target group, T is the total number of individuals in the relevant population, \({S}_{p}\) is the total subsidy received by the targeted population and \({S}_{T}\) represents the total amount of the subsidy distributed. This means that \({\Omega }\) is the share of the subsidy received by the target population over the share of this group in the total population.9 If this indicator is less than one, then it implies that the share of the subsidy accruing to the target population is less than proportional to the share of this group in the population, an indication of regressivity in the targeting of the benefit. If it is greater than 1 then it is progressive (and more so the higher above 1 is this indicator).
One can calculate the Ω index for different definitions of the target population using alternative cut-off points of the income distribution. For example, one target population could be individuals in the lowest three deciles of the income distribution, while an alternative target population could be individuals in the four lowest deciles of the income distribution, and so on. If deciles of the income distribution are used to define the target population, then it is useful to note that the Ω index can be read directly from the Lorenz curve.10 It is equal to the slope of the ray from the origin to the point on the Lorenz curve for the rank threshold defining the target group. It will be less than one if the Lorenz curve is below the 45° line at that point and greater than 1 in the opposite case.
One final point to make is that the incidence of the funding side of the subsidy is also relevant. If some firms increase prices as a result of the Vale Transporte scheme, then how these price increases affect different income groups should be analyzed. Likewise for the public revenue sources for the proportion of benefits funded through tax revenues or deductions. Although analyzing these issues is beyond the scope of this paper, we will present evidence for a third possible funding channel, namely that wages in the formal sector decreased because of the policy. In this case, it would be beneficiary workers themselves who are funding to some extent their own benefits, reducing the effectiveness of the scheme.