Nonparametric multivariate rank tests and their unbiasedness

Although unbiasedness is a basic property of a good test, many tests on vector parameters or scalar parameters against two-sided alternatives are not finite-sample unbiased. This was already noticed by Sugiura [Ann. Inst. Statist. Math. 17 (1965) 261--263]; he found an alternative against which the Wilcoxon test is not unbiased. The problem is even more serious in multivariate models. When testing the hypothesis against an alternative which fits well with the experiment, it should be verified whether the power of the test under this alternative cannot be smaller than the significance level. Surprisingly, this serious problem is not frequently considered in the literature. The present paper considers the two-sample multivariate testing problem. We construct several rank tests which are finite-sample unbiased against a broad class of location/scale alternatives and are finite-sample distribution-free under the hypothesis and alternatives. Each of them is locally most powerful against a specific alternative of the Lehmann type. Their powers against some alternatives are numerically compared with each other and with other rank and classical tests. The question of affine invariance of two-sample multivariate tests is also discussed.Comment: Published in at http://dx.doi.org/10.3150/10-BEJ326 the Bernoulli (http://isi.cbs.nl/bernoulli/) by the International Statistical Institute/Bernoulli Society (http://isi.cbs.nl/BS/bshome.htm

On the dimension of polynomial semirings

In our previous work, motivated by the study of tropical polynomials, a definition for prime congruences was given for an arbitrary commutative semiring. It was shown that for additively idempotent semirings this class exhibits some analogous properties to prime ideals in ring theory. The current paper focuses on the resulting notion of Krull dimension, which is defined as the length of the longest chain of prime congruences. Our main result states that for any additively idempotent semiring $A$, the semiring of polynomials $A[x]$ and the semiring of Laurent polynomials $A(x)$, we have $\dim A[x] = \dim A(x) = \dim A + 1$

Dual Inflation Under the Currency Board: The Challenges of Bulgarian EU Accession

The importance of analysing inflation sources and dynamics in Bulgaria is imposed by (i) the long run process of price and inflation convergence to the Euro area and (ii) by the Currency Board operating in the country. In this study we make an attempt to estimate Balassa - Samuelson (BS) effect in Bulgaria (after the introduction of the Currency Board). The BS explanation of inflation (or dual inflation) has acquired both academic recognition and popularity in practice in the recent years. The results of our empirical estimation do not provide a robust verification of the existence of BS effect in spite of the observed prerequisites and the accompanying economic indicators interrelations. Actually there are several factors that interfere with the BS effect lying in the wage convergence process in both sectors and others that influence productivity developments in the sectors. This prompts that the price movement in the country has other driving motions – above all wage setting and incomplete price liberalization, other factors productivity, imported inflation (pass trough) and inflation generated by the temporary gaps between money demand and money supply.http://deepblue.lib.umich.edu/bitstream/2027.42/39872/3/wp487.pd

Deposit Insurance During EU Accession

The paper presents a brief review of the systems of deposit insurance in accession countries, comparing their level of harmonization with the perspective of their EU integration. Studying the different practices of deposit insurance in the context of developing financial safety nets in future Europe we have found that: (i) there is overinsurance of deposits in accession countries, and (ii) that this could lead to increasing moral hazard, incentives deformation and increasing costs of banking intermediation in the whole euro area.deposits insurance, financial regulation, accession countries

Financial stability, monetary autonomy and fiscal interference: Bulgaria in search of its way, 1879-1913

The Bulgarian monetary system was established, immediately after independence. Having experienced it already under Ottoman rule, newly independent Bulgaria adopted the bimetallic standard. Without being a member of the Latin Monetary Union, it tried broadly to follow the principles of the convention, yet with some exceptions, the most important of which concerned the limit on silver coinage. The absence of such a clause in Bulgaria turned out to be crucial since the financial needs of the recently established state triggered excessive silver coinage which resulted in a persistent agio - a positive and variable difference between the legal and the commercial value of silver coins. The interference of fiscal authorities obstructed the Bulgarian National Bank's ability to manage money in circulation and to secure the monetary stability required by economic development). The attempts of the Bulgarian monetary authorities to eliminate the agio were unsuccessful until they acquired the right to issue silver-backed banknotes. Soon after that, in 1906, Bulgaria introduced a short-lived typical Gold standard.financial stability, monetary autonomy, fiscal interference, Bulgaria

China's exporters and importers: firms, products, and trade partners

This paper provides a detailed overview of China's participation in international trade using newly available data on the universe of globally engaged Chinese firms over the 2003-2005 period. We document the distribution of trade flows and product- and trade-partner intensity across both exporting and importing firms and study the relationship between firms' intensive and extensive margins of trade. We also compare trade patterns across firms of different organizational structure, distinguishing between domestic private firms, domestic state-owned firms, foreign-owned firms, and joint ventures. We explore the variation in foreign ownership across sectors, and find results consistent with recent theoretical and empirical work on the role of credit constraints and contractual imperfections in international trade and investment. Finally, we examine the rapid expansion of China's trade over the 2003-2005 period, and decompose it into its extensive and intensive margins. We also use monthly data and study the frequent churning and reallocation of trade flows across firms and across products and trade partners within firms.

Sharply Orthocomplete Effect Algebras

Special types of effect algebras $E$ called sharply dominating and S-dominating were introduced by S. Gudder in \cite{gudder1,gudder2}. We prove statements about connections between sharp orthocompleteness, sharp dominancy and completeness of $E$. Namely we prove that in every sharply orthocomplete S-dominating effect algebra $E$ the set of sharp elements and the center of $E$ are complete lattices bifull in $E$. If an Archimedean atomic lattice effect algebra $E$ is sharply orthocomplete then it is complete

Assessing Market Expectations on Exchange Rates and Inflation: A Pilot Forecasting System for Bulgaria

Econometric forecasting models typically perform bad in volatile environments as they are often present in economies in transition. Since forecasts of key macroeconomic variable are inevitable as guidelines for economic policy, one might alternatively make attempts at measuring market participants’ expectations or conduct surveys. However, often financial markets are underdeveloped and regular surveys are unavailable in transition countries. In this paper we propose to conduct experimental stock markets to reveal market participants’ expectations. W? present the results fr?m a series of pilot markets conducted in Bulgaria throughout 2002 indicating that the method could be useful especially for transition countries.http://deepblue.lib.umich.edu/bitstream/2027.42/40145/3/wp759.pd