Table 1.
Skewness test of the statistical noise.
Table 2.
Stochastic tax frontier model estimation, panel data for 26 EU countries, 2000–2015.
Table 3.
The marginal effects of the CPI, shadow economy, documents to import and cost to import on the mean E(u) of the inefficiency term ui,t.
Table 4.
Results from panel data STFM estimation of VAT gap using Battese and Coelli [7] model for EU-26 countries, 2000–2015.
Table 5.
The estimation of time-varying and persistent VAT inefficiency by the stochastic tax frontier model for EU-26 countries, 2000–2015.
Table 6.
Results of the STFM estimation of time-varying and persistent technical efficiency VAT and VAT gap using the model of Kumbhakar, Lien and Hardaker [8] for EU-26, 2000–2015.
Table 7.
The changes in VAT gap estimates from 2011 to 2018 calculated by HM revenues & customs in the United Kingdom.
Fig 1.
Time-varying VAT gap and persistent VAT gap in the western group of EU countries.
The blue dotted line represents the time-dependent Value Added Tax gap and the red line represents the country-specific or persistent Value Added Tax gap, between 2005–2015. The persistent and time-dependent VAT gap was generated in STATA after the STFM estimation.
Fig 2.
Time-varying VAT gap and persistent VAT gap in the southern group of EU countries.
The blue dotted line represents the time-dependent Value Added Tax gap and the red line represents the country-specific or persistent Value Added Tax gap, between 2005–2015. The persistent and time-dependent VAT gap was generated in STATA after the STFM estimation.
Fig 3.
Time-varying VAT gap and persistent VAT gap in the eastern group of EU countries.
The blue dotted line represents the time-dependent Value Added Tax gap and the red line represents the country-specific or persistent Value Added Tax gap, between 2005–2015. The persistent and time-dependent VAT gap was generated in STATA after the STFM estimation.
Table 8.
Results from the panel data STFM estimation of VAT gap versus the VAT gap obtained by the CASE [4, 5] top-down method for 2015.
Table 9.
Endogeneity test for the input variable of the stochastic tax frontier model.
Table 10.
Endogeneity test for the environmental variables (Z variables) of the stochastic tax frontier model.