Is the abolition of tax-deductible transportation costs economically grounded?

In the discussion about the abolition of tax deductions, the elimination or reduction of the distance lump-sum for commuting costs is often debated. Prof. Wolfram F. Richter, University of Dortmund, calls for an examination of the concept of transportation costs and the criterion of occupational necessity. Also for Prof. Peter Bareis, University of Stuttgart, the present law is not reasonable: "It should be changed in accordance with the proposal of the 1994 Income Tax Commission, which proposed a limit based on the average costs of local public transportation. This should be supplemented by the assumption of private reasons for travel of approximately one half, or where appropriate by a degression of the deductions depending on the distance. Prof. Dr. Matthias Wrede, Aachen RWTH, also argues for a cut of the distance lump sum, which is "efficient and just", in his opinion. The expenditures of employees for journeys between their homes and their place of work should be deductible as a lump sum "at a rate below the internal marginal costs". In constrast, Dr. Martin Gasche, of the staff of the German Council of Economic Advisers, opposes a further reduction or abolition of the distance lump sums.