Chiral Splitting and N=4\mathcal N = 4 Einstein--Yang--Mills Tree Amplitudes in 4d

We present a world-sheet formula for all tree level scattering amplitudes, in all trace sectors, of four dimensional $\mathcal{N} \leq 4$ supersymmetric Einstein-Yang-Mills theory, based on the refined scattering equations. This generalizes previously known formulas for all-trace purely bosonic, or supersymmetric single-trace amplitudes. We find this formula by applying a new chiral splitting formula for all CHY Pfaffians in 4d, into two determinants, of positive and negative helicity respectively. The splitting of CHY Pfaffians is shown to be a special case of the splitting of $T\mathbb{M}$ valued fermion correlators on the sphere, which does not require the scattering equations to hold, and is a consequence of the isomorphism $T\mathbb{M} \simeq \mathbb{S}^+ \otimes \mathbb{S}^-$ between the tangent bundle of Minkowski space and the left- and right-handed spin bundles. We present and prove this general splitting formula.Comment: 21 page

Silent Interests and All-Pay Auctions

If firms compete in all-pay auctions with complete information, silent shareholdings introduce asymmetric externalities into the all-pay auction framework. If the strongest firm owns a large share in the second strongest firm, this may make the strongest firm abstain from bidding. As a consequence, equilibrium profits of both firms may increase, but the prize may be allocated less efficiently. The reverse ownership structure is also likely to increase the profits of the firms involved in the ownership relationship but without these negative efficiency effects.all-pay auctions, externalities, contests, silent minority shareholdings, ownership structure

Dynamic contests

Considering several main types of dynamic contests (the race, the tug-of-war, elimination contests and iterated incumbency fights) we identify a common pattern: the discouragement effect. This effect explains why the sum of rentseeking efforts often falls considerably short of the prize that is at stake. It may cause violent conflict in early rounds, but may also lead to long periods of peaceful interaction. -- Unter Berücksichtigung verschiedener Haupttypen dynamischer Wettbewerbe (das Wettrennen, das Tauziehen, Ausscheidungskämpfe und wiederholte Kämpfe um Amtszeiten) identifizieren die Autoren ein gemeinsames Muster: den Entmutigungseffekt. Dieser Effekt erklärt, wieso die Rent-seeking-Bemühungen in Summe oft deutlich nicht an den auf dem Spiel stehenden Preis heranreichen. Der Effekt kann heftige Kämpfe in den ersten Runden des Wettbewerbs auslösen, aber auch zu langen Perioden friedlichen Zusammenspiels führen.

Investment in the Absence of Property Rights: The Role of Incumbency Advantages

In many situations the individuals who can generate some output must enter a contest for appropriating this output. This paper analyses the investment incentives of such agents and the role of incumbency advantages in the contest. Depending on the advantages, an increase in the productivity of the investment can decrease or increase the amount of investment. The results are applied to autocrats' investment behavior and job specific investment in organizations.investment, endogenous property rights, contests, incumbency advantage, proprietary states

Terrorism and the state

This paper considers terrorism as an extortion activity. It uses tools from the theory of extortion and from conflict theory to describe how terrorism works, why terrorism is a persistent phenomenon, why terrorism is a violent phenomenon, and how retaliation affects the outcome. The analysis highlights the importance of information aspects and discusses some aspects of the organizational design. -- Anhand der frühen terroristischen Organisation der Ismaili aus dem 11. bis 13. Jahrhundert wird deutlich, dass zwischen Schutzgelderpressung und Terrorismus keine klare Trennlinie existiert. Die Ismaili waren zeitweise als Staat organisiert, teilweise eine Organisation ohne eigenes Territorium. Sie nutzten die gleichen Instrumente zur Durchsetzung politischer, religiöser und rein finanzieller Ziele. Diese strukturelle Äquivalenz wird genutzt, um einige Ergebnisse aus der Theorie der Schutzgelderpressung für das Verständnis der Funktionsweise von Terrorismus abzuleiten. Die formale Analyse konzentriert sich dabei auf ein fundamentales Informations- und Glaubwürdigkeitsproblem, das anhand der Berichte über die Ismaili deutlich wird. Dieses Informationsproblem kann erklären, weshalb Terrorismus ein mehrperiodisches Phänomen ist, warum Terrorismus mit Gewalt einhergeht, weshalb Terroristen eine öffentliche Sichtbarkeit ihrer Anschläge bevorzugen und wie Gegenschläge und Versuche der Zerschlagung einer terroristischen Organisation in diesem Zusammenhang zu bewerten sind. Kurz werden weitere Aspekte diskutiert, die für das Verständnis von Terrorismus wichtig sind, in der formalen Analyse aber ausgeblendet werden.Terrorism,extortion,credibility,retaliation,Ismaili

Inverse Campaigning

It can be advantageous for an office motivated party A to spend effort to make it public that a group of voters will lose from party A’s policy proposal. Such effort is called inverse campaigning. The inverse campaigning equilibria are described for the case where the two parties can simultaneously reveal information publicly to uninformed voters. Inverse campaigning dissipates the parties' rents and causes some inefficiency in expectation. Inverse campaigning also influences policy design. Successful policy proposals hurt small groups of voters who lose much and do not benefit small groups of voters who win much.inverse campaigning, information, voting, policy design

Information alliances in contests with budget limits

We study the role of information exchange through alliances in a framework with contestants who have binding budget limits and know their own budget limit but are incompletely informed about other contestants' budget limits. First, we solve for the Bayesian Nash equilibrium. Then we consider the role of information exchange through alliances. Contestants learn the budget limits of all players who are within the same alliance, and then decide independently about their own contest efforts. This type of alliance formation is beneficial for alliance members and neutral for players who do not belong to the alliance. Also, a merger between alliances is beneficial for their members. Further, we consider merger between alliances and discuss the set of stable combinations of alliances. --Contest,budget limits,incomplete information,alliances,information sharing

Search costs and corporate income tax competition

This paper studies corporate tax competition if it is costly to learn some of the elements that determine the effective tax burden. Search cost may, but need not, eliminate the tax competition pressure. The outcome depends on the boundaries of tax rate and tax base choices. Search cost can explain the empirically observed tax cuts cum base broadening. -- Dieser Artikel untersucht den Körperschaftssteuerwettbewerb und insbesondere die Frage, ob es kostspielig ist, einige der Elemente in Erfahrung zu bringen, welche die effektive Steuerbelastung bestimmen. Suchkosten können, müssen aber nicht, den Druck des Steuerwettbewerbs aufheben. Das Resultat hängt von der Wahl der Steuerfreigrenzen und der Steuerbemessungsgrundlage ab. Suchkosten können die empirisch beobachteten Steuersenkungen, verbunden mit der Verbreiterung der Steuerbemessungsgrundlage, erklären.Costly search,tax competition,corporate taxation,monopoly pricing paradox

Mobile Tax Base as a Global Common

If countries anticipate Bertrand competition in tax rates, they may expend effort that makes some of their tax payers less mobile or increases the mobility of tax payers elsewhere. I provide piecemeal evidence on what activities countries use. I analyse how such activities interact with Bertrand tax competition if the size of the group of loyal and non-loyal citizens or investors is endogenous. Further I consider the implications of tax harmonization and minimum taxes for these types of non-price competition. Home attachment reduces the intensity of tax competition, but generates a strategic disadvantage for the country that invests much in such home attachment. Harmonization of taxes and high minimum taxes can intensify countries’ investment in home attachment.tax competition, common pool, advertizing, nation brands, instilling preferences, home bias, patriotism