INTERNATIONAL AVERAGE PRICES AND COMPARISONS OF NATIONAL AGGREGATE PRODUCTION OF AGRICULTURE

"The whole question of making inter-spatial comparisons between countries is a most complicated and hazardous business" (Mr. Campion); international comparisons of a particular value aggregate between countries present a difficult problem connected with the conversion of national value aggregates into a comparable magnitude. This paper presents an alternative approach in that an internationally comparable value aggregate for each country is prepared by the international average prices of commodities which are determined simultaneously with the partial exchange rates of national currencies to a standard currency. The calculated partial exchange rates are so defined as to reflect the purchasing power of national currencies in respect of the group of commodities selected. Consequently, the resulting value aggregate for international comparison has a quantity dimension, eliminating the effect due to the different purchasing power of national currencies in which original prices are quoted. The other methods of international comparison so far being used by other research workers, such as C. Clerk and M. Gilbert and his associates, are examined in the light of the properties of the present method and the crucial differences are delineated. Using the method proposed, an international comparison is made of the aggregate value of agricultural products for 11 selected countries in the world, with sub-divisions into two regions.     

Matrix exponential GARCH

I propose a new multivariate GARCH specification that maintains positive definiteness of the conditional covariance matrix. The idea is to specify the dynamics in the matrix logarithm of the conditional covariance. Because the matrix exponential transformation ensures positive definiteness, the dynamics can be specified without the positive definiteness constraint. This affords a variety of specifications and, in particular, we can specify element-by-element the dynamics of the matrix logarithm. I discuss specifications with leverage effects, estimation with multivariate Gaussian and t-distributions, and diagnostics that evaluate the appropriateness of the matrix exponential specification.     

AN EMPIRICAL EXAMINATION OF FINANCIAL LIBERALIZATION AND THE EFFICIENCY OF EMERGING MARKET STOCK PRICES

The efficient markets hypothesis in finance suggests that as equity markets are liberalized and made more open to the public, equity prices should reflect the increased availability of information and be more efficiently priced. In this paper, we examine whether emerging market equity prices have become more efficient after financial liberalization. Using two sets of financial liberalization dates, a battery of econometric tests, and data from sixteen countries and three composite portfolios, we find that in spite of theory suggesting the opposite, liberalization does not seem to have improved the efficiency of emerging markets. In fact, most of our statistical tests indicate that the markets were already efficient before the actual liberalization.