Underestimation or overestimation of tax revenues may result from poor forecasting or/and ineffective tax revenue collection. Therefore, to understand forecasting deviations, there is a need to identify the factors that hinder government efforts to accurately predict future revenue sources and/or those that result in ineffective tax collection. This paper argues that a government’s political and institutional characteristics may influence (or encourage) deviations in tax revenue forecasting. To our knowledge, only one article analyses the influence of an index of budget transparency on budget forecast tax revenue deviations – Ríos et al. (2018). They used a sample of the 100 largest Spanish municipalities during the period 2008–2014, showing that budget transparency influences budget forecast tax revenue deviations. Less budget-transparent municipalities tend to overestimate their tax revenues, which enables them to expand public goods and services without raising taxes immediately. These municipalities may spend less than they planned since they are aware of the overestimation of their tax revenues. While less budget-transparent municipalities overestimate their tax revenues, more budget-transparent municipalities appear to be more conservative in their estimates and underestimate their tax revenues, allowing them to spend more than projected.
The public policy cycle in LGUs is a process of six stages: determination of the agenda, policy formulation, budget forecasting, budget implementation, evaluation and policy change (Ríos et al., 2018). This paper focuses on budget forecasting and forecasting revenues, which is one of the most significant issues in public budgeting. Budget analysts might forecast revenues and expenditure line items with few inaccuracies, but forecasting also serves additional purposes that benefit politicians. In this sense, budget transparency may be a tactic to improve the decision-making process and lessen the motivation for politicians to manipulate the predictions for their objectives. In light of this, this article empirically analyses the impact of OLBT on budget forecasting in tax revenues.
Lago-Peñas & Lago-Peñas (2004), using Spanish municipalities during the period 1985–1995, demonstrated the importance of the political power of the incumbent and the electoral cycle. Deficit forecasting deviations are lower for incumbents with a single-party majority and more significant during election years and for smaller municipalities. Additionally, population size is inversely connected with the variability of deviations; this may be explained if officials’ technical capacity increases with LGU size. In contrast, their estimations indicate that the impact of ideology and of the disintegration of ruling coalitions on deficit deviations is significant. As a result, political variables play a role in the positive association between budgetary flexibility and actual budgets observed in empirical research on the causes of public deficits. They tested how the search for political support ultimately leads to overestimating public deficits when (i) budget procedures are soft, (ii) breaking promises made on higher expenditures and the lowering of taxes is costly in political terms, and (iii) ex-post control by voters and political opposition is imperfect. According to econometric forecasts, incumbents with a single-party majority are less likely to change forecasted budgets. They tend to have more significant anticipated deficits but smaller actual deficits, which might be attributed to greater regularity in the financial process. Second, deficit upward deviations typically increase during election years. Forecasted deficits do not change during election years, but actual deficits do. Additionally, elections result in consistent declines in revenues. The incumbent’s ideology, on the other hand, is irrelevant when attempting to explain deficit deviations.
Bischoff & Gohout (2006; 2010) used ten West German states during the period 1992–2002. Bischoff & Gohout (2006) showed that governments often overestimate their forecasts of tax revenues, while Bischoff & Gohout (2010) found that governments commonly overestimate tax revenue during election years. Bischoff & Gohout (2006) contend that incumbent state lawmakers may do this to raise expenditures, increasing the debt and, therefore, their chances of winning re-election. The degree of overestimation is not affected by elections or partisanship, but it is discovered that the politician’s popularity has a significant impact. The degree of overestimation in tax revenues increases with the popularity of the incumbent’s party and, thus, with the likelihood of its being re-elected. This finding lends credence to the idea that due to the uncertainty of re-election, governments accept deficits to accelerate expenditures that were initially budgeted for future periods. Since tax estimates are invisible ex ante, unlike open deficits, they have a special allure when used for this purpose. As a result, they are exempt from constitutional limitations on public deficits. Furthermore, they are probably less damaging to the incumbent’s perceived valence and consequent popularity. To improve external control, the budget process must be transparent. Bischoff & Gohout (2010) found that governments that are unsure whether they will be re-elected should provide overly optimistic tax revenue forecasts every year. The greater the degree of overestimation, the less popular politicians are. These findings support the idea that the uncertainty of re-election induces governments to tolerate deficits to accelerate expenditures that were initially budgeted for later periods and/or impose more debt on future governments. According to the same article, overestimated forecasts of tax revenues are a substitute for explicit deficits. Governments that overestimate tax revenues can incorporate increased expenditures without obviously increasing debt levels if they disclose exaggerated tax revenues. In contrast, they can lower explicit deficits without reducing expenditures. According to the literature, an incumbent party may benefit from this potential in two ways. It can first exploit overestimated forecast tax revenues to boost its chances of winning re-election. Second, it may advance future expenditures that benefit its constituency or put financial constraints on future governments if re-election appears questionable or improbable.
Goeminne, Geys & Smolders (2008), using a sample of 242 Flemish municipalities during the period 1992–2002, conclude that two-party governments are more optimistic than single-party governments. Governments with at least three parties are much more cautious (or less optimistic) in their forecast revenues than single-party or two-party governments. Extending this study, Chatagny & Soguel (2012) used 26 Swiss cantons between 1980 and 2002 to show that underestimating tax revenue considerably lowers fiscal deficits. Furthermore, they demonstrated that a decline in expenditures mediates this benefit. Overestimation and underestimation have symmetrical consequences on budgetary deficits. Thus, this study proves that conservative tax revenue forecasts lower fiscal deficits and supports the inverse claim that conservative tax revenue budgeting additionally increases budgetary deficits.
Benito et al. (2015), using 2,644 Spanish municipalities with populations of over 1,000 during the period 2002–2010, examine electoral cycle-influenced opportunism in the drivers of municipalities’ budget forecast quality. In their efforts to gain popularity and electoral support, incumbents overestimate revenue in order to spend more, and they underestimate expenditures. These authors prove that the budget forecasting process has to be open and subject to external auditing or oversight. Their findings demonstrate that opportunistic behaviour is influenced by the electoral cycle. They identify two manipulation techniques: (1) since incumbents match anticipated revenues to budgeted expenditures, they overestimate revenue, which enables them to spend more; (2) actual spending in the pursuit of greater approval and electoral support surpasses projected spending. As a result, if there is no legal consequence or public disapproval, governments can manipulate budget estimates in accordance with the timing of elections.
Sustainable budgets serve as crucial quality indicators for the electorate. Politicians may therefore be motivated to make an impact on tax revenue forecasts, which are frequently viewed as a crucial component of long-term national budget planning. Jochimsen & Lehmann (2017), using 18 OECD countries during the period 1996–2012, assessed whether national tax revenue forecasts are skewed as a result of political manipulation. Using political economy theories, they found support for partisan politics. Left-wing governments tend to produce more optimistic or less pessimistic tax revenue forecasts than right-wing governments. Theoretically, the common pool problem predicts that more fragmented governments will create more pessimistic or less optimistic tax revenue forecasts. Politicians may be likely to have an incentive to manipulate tax revenue projection because it serves as the foundation for the government’s expected total revenues, and there are various justifications for this behaviour in the theoretical political economics literature.
Cuadrado-Ballesteros et al. (2021), using a sample of 140 Spanish municipalities for the period 2008–2018, examine the impact of the gender of the mayor and the proportion of female councillors in the local council on tax revenue deviations. Municipalities with female mayors and a higher proportion of female councillors tend to overestimate tax revenues, leading to poor financial conditions. These effects are reversed when the proportion of female councillors is relatively high: municipalities then tend to underestimate tax revenues, which leads to better financial conditions. These findings highlight the relevance of considering the nonlinear influence of women councillors in local councils because women’s expected effect might contribute to LGUs’ financial health (Cuadrado-Ballesteros et al., 2021). Female involvement in LGUs enhances the likelihood that fiscal and financial stability legislation will be followed. The findings suggest that because women tend to adopt a more pessimistic budgeting perspective, causing LGUs to underestimate budgeted tax revenues, women’s presence in LGU councils can improve their financial situation; this is in addition to the moral obligation to promote gender diversity and equality of opportunities between men and women. However, to achieve this favourable outcome, their numbers must be relatively substantial; otherwise, the interests and viewpoints of the few women may be diluted among their male counterparts, who hold various viewpoints as per the stereotypes put out by social role theory.
Bohn & Veiga (2021) proved three propositions of political forecast cycle (PFC) models. First, incumbent politicians may lower their revenue forecasts if the ex ante forecast winning margin is higher. Second, when the incumbent politician is not running, his or her incentive to win the elections is diminished, and opportunistic manipulation is reduced. Third, any form of budget manipulation is more successful if there are more uninformed voters. These three propositions were tested and proven using 308 Portuguese municipalities during the 1998–2017 period. The findings unmistakably show that there is revenue forecast manipulation in election years and that the manipulation is smaller when higher-win margins were evidenced at the previous elections, when the incumbent politicians do not offer themselves for re-election, and when the municipality’s population has a lower level of education.
Couture & Imbeau (2009), Anessi-Pessina & Sicilia (2015), and Boukari & Veiga (2018) have used political and electoral variables, such as political ideology, the closeness of local elections, and the fragmentation of government, to explain the presence of variations in local planned tax revenue. Additionally, they have accounted for other socioeconomic aspects, including unemployment, economic level, fiscal/budget transparency, financial situation, and fiscal regulations. Some researchers claim that politicians may be motivated to interfere with public expenditures to accomplish personal goals. Alesina and Perotti (1999) point out that politicians may purposely overestimate tax revenue, leading to more significant deficits. Politicians might use this tactic to blame deficits on the technological challenges involved in forecasting future tax revenue. Van der Ploeg (2010) has theoretically demonstrated that it may be preferable to purposely underestimate the tax base to restrain expenditure and politicians’ financial appetites and minimise debt. The government reduces debt by raising taxes and lowering public expenditures to protect against future shocks. Chatagny & Soguel (2012) contended that such a buffer may be produced by underestimating tax revenues to restrain expenditures, generate extra revenue as a result, and reduce the deficit. However, a precautionary buffer may be created to boost expenditure in an election year (Bischoff & Gohout, 2010; van der Ploeg, 2010). Therefore, careful planning of tax revenues does not ensure that deficits and debt will be minimised.
According to two theories, incumbent politicians typically choose to be ambiguous. First, fiscal illusion theory suggests that uninformed and naive voters frequently underestimate the costs of ongoing and upcoming public projects, especially when budgets are not fiscally transparent. However, governments can distort budget estimates to suit their preferences due to a lack of transparency. Politicians may, therefore, be influenced by incentives to be either optimistic or pessimistic (Mayper et al., 1991; Chatagny & Soguel, 2012; Goeminne et al., 2008). Governments might enhance services without raising taxes right away or meet the need for a balanced budget by being too optimistic about revenues. Additionally, optimistic revenue projections have a smaller political cost than higher taxes in terms of votes lost. The second, principal-agent theory, claims that voters and incumbent politicians may not have the same goals in mind since politicians occasionally prioritise their interests, which do not always maximise voters’ welfare. Voters can likewise not assess incumbents’ competency, which is their capacity to offer particular service levels at the lowest taxes. To enhance their chances of being re-elected, incumbents make an effort to demonstrate their competence to the public, especially when elections are close. As a result, a lack of budget transparency may provide politicians with a competitive advantage in attaining their objectives and allow LGUs to customise budget predictions according to their preferences to appear competent to voters and, as a result, increase their chances of re-election. The models of PBCs suggest that LGUs would try to implement more popular policies shortly before an election. Similarly, more unpopular policies are implemented shortly after elections. To increase their prospects of winning elections or gaining re-election, politicians may make overly optimistic projections of budget variables, which causes revenues to be overestimated (Drazen, 2008). On the one hand, they can predict optimistic revenues and receive more support from the public and politicians before elections (but they also run the danger of damaging their brand if they do not fulfil their forecasts). On the other hand, they might offer gloomy budget revenue forecasts, which have a negative impact on both ex ante and ex post reputations. Pessimistic revenue projections (underestimation) may provide a buffer for unforeseen costs or revenue shortfalls and demonstrate that wise management produces year-end operational savings.
Third-generation models of PBCs include models based on the limited rationality of voters and have been proposed by scholars such as Bohn (2018), Bohn & Veiga (2021) and Crombach & Bohn (2022). The previous two generations include models based on information asymmetry (Rogoff, 1990; Rogoff & Sibert, 1988) and a model based on moral hazard (Shi & Svensson, 2006). They cannot explain why political budget manipulations occur and systematically increase the chances of re-election or that the PBC is conditioned by a specific institutional context, i.e., in budget non-transparent governments. PFCs introduce unsophisticated (poorly informed) voters and explain that the vote share of the current politician in power increases due to his or her electoral manipulations. The increased suspicions of unsophisticated voters are reinforced by the PBC, while the manipulations of politicians must be stronger than the suspicions of unsophisticated voters to be effective. The effect produced by unsophisticated voters on political cycles is studied in the context of forecasting manipulation. Some of the motives for forecast manipulation are as follows: (a) the politician is too optimistic (overestimates revenues) to have more room for manipulation before the election, or (b) the politician is too pessimistic (underestimates the budget balance) to demonstrate his own level of competence by being able to implement unexpected expansionary fiscal policies. Manipulations based on overly optimistic forecasts before upcoming elections create PBCs and lead to budget deficits before elections despite the existence of a balanced budget obligation.
As previously stated, although certain theories contend that some politicians lack the motivation to provide financial information, budget transparency is increasing due to, among other things, outside demands and limits. However, there are meaningful variations in the level of OLBT and the precision of budget forecasts between LGUs, which raises the possibility that these discrepancies are not accidental (Williams & Calabrese, 2016). The lack of budget transparency may give politicians more chances to use optimistic or pessimistic budget forecasts to persuade voters. In this regard, we state the hypothesis that the level of OLBT has a significant impact on tax revenue forecasting.