Competition and efficiency: application to tax haven, profit shifting and platform competition
Oh, David Kyungtaek
The first chapter considers the tax information exchange agreement as a way to draw Pareto improvement between off-shore tax havens and non-haven countries. Individuals who reside in a non-haven country choose the volume of tax evasion to maximize the expected payoff which depends on the tax rate and the probability of being detected. A tax haven might be reluctant to sign a TIEA since establishing a TIEA increases the probability of detection thus decreasing the volume of individuals' tax evasion ceteris paribus. However, we find that establishing a TIEA makes the non-haven country increase the tax rate so that both tax evasion and welfare increase. This is because non-haven country government catches tax criminals with greater probability so it can handle greater volume of tax evasion under higher tax rate. Because not only the non-haven country's welfare but also the capital inflow into the tax haven are increased, tax havens would sign TIEAs with non-haven countries voluntarily in anticipation of greater future payoff. The second chapter, I, jointly with Dr. Mongrain and Dr. Ypersele, develop a continuous fiscal competition model in which two countries compete over multinational firms (MNF) by varying the tax rates and the tightness of profit shifting control. Being loose on profit shifting decreases the tax base of one country but at the same time it brings two benefits. First, the country attracts more MNFs for given tax rate. Second, loose control of one country allows the other country to set high tax rate by alleviating the pressure of tax competition. Since the tax rates of the two countries are strategic complements, both countries can achieve efficiency gain by not actively controlling international profit shifting. We also show that relaxing the profit shifting regulations can reduce the equilibrium tax gap between high tax region and low tax region. This is because the high tax region's tax choice is generally more sensitive to the profit shifting control. As all the downward forces on the tax rate choices, which are resulted by the location effect and per-firm profit shifting effect, are positively related to the equilibrium tax gap, choosing the lax profit shifting control may close the tax gap and lead to the higher tax revenue even for the high tax region. The third paper studies the competition in the platform markets where companies improve the quality standard to attract the consumers. In some platform markets, e.g. video game industry, improving the quality standard decreases the number of software developed due to the greater pressure of development cost. Such disadvantage of the quality upgrade in one platform is spread to its competitors because all the platforms share a certain portion of video game software through `porting.' Because of the negative externality created by porting, the platforms tend to increase the quality standard by extra amount. Our model shows that the quality competition in the competitive market is excessive because the platforms fail to internalize the inter-platform externality.