samlet årgang - Økonomisk Institut - Københavns Universitet

Nationaløkonomisk Tidsskrift 143 (2005): 380-415
Skattekonkurrence og økonomisk
geografi
Niels Johannesen
E-Mail: nielsjohannesen@gmail.com
SUMMARY: Whilst simple theoretical models of tax competition suggest that international
capital mobility reduces the capital tax rate in equilibrium, empirical studies
conducted in the field have produced ambiguous results. This paper argues that
the puzzling empirical findings may be due to an omitted variables bias and mitigates
the bias by estimating a comprehensive model for capital taxation controlling for
tax export effects, productivity effects of public goods as well as agglomeration
effects. The estimated impact of increased capital mobility in the OECD-countries
between 1975 and 2000 was a reduction of average capital tax rates of around 10 percentage
points. In the same period, however, decreasing trade barriers in the goods
markets boosted economic rents in capital agglomerations triggering an increase in
capital tax rates of a similar magnitude. In brief, this paper finds strong evidence of
tax competition between OECD-countries and demonstrates that its effects have so far
been neutralized by spill-over effects from the goods markets. The policy implications
of these results are remarkable. Since agglomeration rents can be shown to be a humpshaped
function of trade costs, further integration of goods markets will arguably
reinforce the effects of tax competition rather than counterbalancing these effects as
hitherto observed. Consequently, there would be an increased need for international
policy coordination in the field of capital taxation.
1. Indledning
Helt centralt i den teoretiske litteratur om skattekonkurrence står påvisningen af
en negativ sammenhæng mellem international kapitalmobilitet og kapitalbeskatning: I
tilstedeværelsen af kapitalmobilitet er kapitalbeskatning forbundet med en omkostning
i form af kapitaludstrømning, og dette resulterer i et nedadgående pres på kapitalskatteraten.
Argumentet synes overbevisende, men ikke desto mindre har det vist sig
vanskeligt at etablere en sådan sammenhæng empirisk. Adskillige studier finder i modstrid
med den teoretiske skattekonkurrencemodel en positiv empirisk sammenhæng
mellem kapitalmobilitet og kapitalbeskatning.
I denne artikel søges en forklaring på uoverensstemmelsen mellem litteraturens teoretiske
og empiriske resultater: I et teoretisk afsnit identificeres yderligere tre faktorer,