They are the authors of "The Myth of Ownership: Taxes and Justice."
Says it all.
There was good reason why Karl Marx and the Communist Party makes the progressive/graduated income tax the 2nd plank of the Manifesto of the Communist Party.
We should never forget nor overlook the philosophical underpinnings of that choice, which truly condemns private ownership at any level:
"The proletariat will use its political supremacy to wrest, by degree, all capital from the bourgeoisie, to centralize all instruments of production in the hands of the state ... . Of course, in the beginning, this cannot be effected except by means of despotic inroads on the rights of property ... . These measures will, of course, be different in different countries. Nevertheless, in most advanced countries, the following will be pretty generally applicable.
1. Abolition of property in land and application of all rents of land to public purposes.
2. A heavy progressive or graduated income tax.
3. Abolition of all rights of inheritance.
4. Confiscation of the property of all emigrants and rebels.
5. Centralization of credit in the banks of the state, by means of a national bank with state capital and an exclusive monopoly.
6. Centralization of the means of communication and transport in he hands of the state.
7. Extension of factories and instruments of production owned by the state; the bringing into cultivation of waste lands, and the improvement of the soil generally in accordance with a common plan.
8. Equal obligation of all to work. Establishment of industrial armies, especially for agriculture.
9. Combination of agriculture with manufacturing industries; gradual abolition of all the distinction between town and country by a more equable distribution of the populace over the country.
10. Free education for all children in public schools. Abolition of children's factory labor in its present form. Combination of education with industrial production, etc. "