The article shows that the credits granted by resident banks to the corporate sector (resident banks, resident legal persons, and resident individuals legal persons - individuals – residents) have an impact on Ukraine's budget revenues and assesses this impact for 2006–2015.
As to the methodology of assessment, which is based on tax accounting of the credit transactions, it has been proved that the corporate sector's credit transactions are subject to one tax, which is corporate tax. The author identifies five components of profit obtained from the corporate sector's credit transaction (the amount of accrued interests on loans granted to non-payers of corporate tax in national and foreign currencies; the amount of exchange rate differences on loans granted in foreign currency to non-payers of corporate tax; the amount of exchange rate differences on interest indebtedness on loans granted in foreign currency to non-payers of corporate tax; increment of insurance reserves made on loans granted in national and foreign currencies to the corporate sector; and the sum of amount of exchange rate differences on insurance reserves made on loans granted to the corporate sector in foreign currency). Based on the generalized the formula of payments of the corporate tax on credit transactions of the corporate sector, the author calculates the estimates of the impact of such transactions on the amount of corporate tax, which are also estimates of the impact of credit transactions on the revenues of Ukraine's budget.
The calculations have proved that the corporate sector's credit transactions increase Ukraine's budget revenues. Definitely positive for Ukraine's budget revenues is the impact of accrued interests on loans granted to non-payers of corporate tax in national and foreign currencies. Other components of profits gained by the corporate sector from its credit transactions have mixed impact on Ukraine's budget revenues, due to jumps of the official exchange rate of the US dollar.

Keywords: corporate sector's credit transactions, budget revenues, profit, corporate tax, accrued interests on credit, exchange rate differences, banks' insurance reserves

The author notes that, in their studies on fiscal policy, Ukrainian scientists are now beginning to use fiscal sustainability indicators. However, some researchers allow themselves to freely treat the formulas of these indicators (by discarding individual components or introducing new variables), which calls into question the results of calculations and conclusions drawn from them. The article reveals the origin of the formulas for fiscal sustainability indicators. The author presents the derivation of a one-period budget constraint in relative variables, a budget constraint for a finite period of time and a budget constraint for an infinite period of time (intertemporal budget constraint). The content of the no-Ponzi game condition is revealed.
The author shows how the formula for calculating the indicator of medium-term fiscal sustainability S1 is derived from a budget constraint for a finite period of time, and the formula for calculating the indicator of long-term fiscal sustainability S2 – from an intertemporal budget constraint. The meaning of these indicators and their components is explained in accordance with the interpretations of the Europe-an Commission. Identified parameters whose values affect the values of fiscal sustainability indicators. It is shown which target values of public debt are selected by the countries that compile reports on fiscal sustainability. The author provides the items of revenues and expenses, whose impact on fiscal sustainability is investigated in different countries and gives a concept of basic and alternative calculation scenarios.
The example of Canada and the European Union shows the values of the parameters of the medium-term fiscal sustainability indicator S1 in the baseline scenario and what values these parameters may have in the alternative scenarios. It is noted that, with the help of fiscal sustainability indicators, it is possible to assess the sustainability of both the general government budget and budgets of lower levels, as well as budgets of state social insurance funds. Presented the classification of the risks to fiscal sustainability in the medium and long-term periods, which is used by the European Commission. On the example of Ukraine, the author shows the sensitivity of medium-term fiscal sustainability indicator to changes in the values of its parameters. The process of decision-making on fiscal policy with the help of fiscal sustainability indicators S1 and S2 is illustrated. Highlighted the points that need to be considered when calculating the indicators' values.

Keywords: fiscal policy, fiscal gap, fiscal sustainability, fiscal sustainability indicators, budget constraints

To assess fiscal sustainability, the European Commission uses the medium-term and long-term fiscal sustainability indicators S1 and S2. Variables in the formulas of these indicators are compiled according to the methodology of the European System of National and Regional Accounts 2010 in accordance with the Eurostat’s Manual on Government Deficit and Debt. Ukraine compiles the government finance statistics in accordance with the 1986 IMF’s Government Finance Statistics Manual.
The same variables of the government finance statistics, compiled according to different methodologies, have different data coverage. Therefore, in Ukraine it is impossible to unconditionally use the formulas of the fiscal sustainability indicators S1 and S2, whose variables are compiled according to the European methodology. The author adapts the fiscal sustainability indicators S1 and S2 to the government finance statistics compiled according to the Ukrainian methodology.
The adapted medium-term and long-term fiscal sustainability indicators S1^а and S2^а differ from their European analogues in that they use the variable of adjusted primary balance instead of the variable of primary balance. The author builds the adapted medium-term and long-term fiscal sustainability indicators S1^ав and S2^ав taking into account the currency structure of government debt. They differ from the adapted fiscal sustainability indicators S1^а and S2^а, which do not take into account the currency structure of government debt, in that they use the adjusted effective nominal interest rate on the government debt instead of the effective nominal interest rate on the government debt.
The difference between the adapted medium-term fiscal sustainability indicators that take into account and do not take into account the currency structure of government debt (S1^ав–S1^а), as well as the difference between the adapted long-term fiscal sustainability indicators that take into account and do not take into account the currency structure of government debt (S2^ав–S2^а), show the values by which the budget expenditures on the government debt servicing should be additionally adjusted so that such expenditures correspond to the target currency structure of government debt in the medium and long term, respectively.
The retrospective data of Ukraine’s government finance statistics (2005-2018), compiled in accordance with the Ukrainian methodology, show how wrong are the estimates of medium-term fiscal sustainability obtained with the use of the European formula of the medium-term fiscal sustainability indicator S1, as well as calculate the estimates of additional adjustments to the Ukraine’s State Budget expenditures on the Ukrainian government debt servicing for different scenarios of the formation of the currency structure of Ukrainian government debt in 2006-2018.

Keywords: fiscal gap, fiscal sustainability, fiscal sustainability indicators, adapted fiscal sustainability indicators, currency structure of government debt

The example of Ukraine shows that the indicator of fiscal sustainability s1a for one year can be used to diagnose the current state of the state budget. Six principles of construction of such an indicator are considered, which include: 1) construction of the indicator s1a for the current year; 2) calculation of the value of the indicator s1a for the current year every month, that is, with the frequency with which information on the implementation of the Ukraine's State Budget for the period from the beginning of the current year to the current month of the current year is published; 3) calculation of the indicator s1a based on the planned value of the state debt of Ukraine at the end of the current year, the actual value of the state debt of Ukraine at the end of the previous year, the planned and forecast values for the current year of the rest of its components; 4) the assumption that the planned values of the components of the indicator s1a are those whose values are approved in the regulatory and legal acts of Ukraine for the current year (namely: the Resolution of the Cabinet of Ministers of Ukraine on approval of the forecast of economic and social development of Ukraine regarding the nominal GDP and the Law of Ukraine on the State Budget of Ukraine for the current year regarding the remaining components) or calculated based on the above mentioned approved values; 5) the assumption that the planned values of components of the indicator s1a for a month of the current year are equal to one twelfth of their planned values for the current year; 6) the assumption that the forecast values of the components of the indicator s1a for the current year are equal to the sum of their actual values for the period from the beginning of the current year to the current month of the current year and their planned values for the current month and the following months of the current year.
It is indicated that when constructing the indicator s1a on the specified principles, it can be calculated not only as a fiscal gap of the one-year budget constraint, but also in two alternative ways: by calculating the difference between the actual value of the change in the state debt of Ukraine for the period from the beginning of the current year to the current month of the current year and its planned value for this period, as well as by calculating the difference, taken with the opposite sign, between the actual value of the adjusted balance of the State Budget of Ukraine for the period from the beginning of the current year to the current month of the current year and its planned value for this period.
The author reveals the diagnostic capabilities of the indicator s1a, namely: the ability to reflect the current state in the state finance sector, as well as in the financial sector in whole, the ability to define the impact of its components on it, the ability to define the impact of amending the Law of Ukraine on the State Budget of Ukraine for the current year and the Resolution of the Cabinet of Ministers of Ukraine on approval of the forecast of economic and social development of Ukraine on it. It is noted that the use of the indicator s1a will strengthen the validity of decisions on issues of fiscal and debt policy.

Keywords:fiscal gap, fiscal sustainability, fiscal sustainability indicator, State budget of Ukraine, fiscal policy, debt policy