Marketing cooperative vs. commission agent: The Turkish dilemma on the modern fresh fruit and vegetable market

In Turkey, the Wholesale Markets Law was enacted in 1995 to facilitate small-scale growers’ access to the fresh produce market. Cooperatives and commission agents have thus become the main marketing structures available to small-scale fresh produce growers, to supply supermarkets and comply with their new requirements. In this paper, we question the advantages and disadvantages that confront small farmers with respect to those marketing structures to allow for market matching or quality upgrading. Drawing on ownership and transaction cost arguments, we use an analytical framework to identify and compare the costs of these marketing organizations. Based on data collected through a large number of interviews with stakeholders, we show that commission agents and credit cooperatives tend to be more efficient than traditional cooperatives as regards sales performance and decision costs. However, the lack of apparent competition between commission agents does not allow for sufficient provision of incentives for producers to invest in high-quality production. Consequently, credit cooperatives are the only structure progressively turning to strategies of quality upgrading and supermarket supply. The flipside of such strategies is that they may lead to the marginalization of small-scale farmers.     

Dummy variables and predictive tests for structural change

We propose a dummy variable interpretation and an alternative proof of the predictive Chow test; we further show that it provides useful additional information on structural changes. We apply this approach to the St. Louis equation.     

The Cochrane-Orcutt procedure numerical examples of multiple admissible minima

We present two numerical examples of multiple admissible minima obtained by using the Cochrane-Orcutt iterative technique: a forgotten and somewhat farfetched example, constructed by Hildreth and Lu, and a new example, based on more typical economic data.     

Trade policy and quality leadership in transition economies

Trade policy and quality leadership in transition economies are analyzed in a duopoly model of trade and vertical product differentiation. We first show that the incidence of trade liberalization is sensitive to whether firms in transition economies are producers of low or high quality. Second, we find that neither free trade nor the absence of a domestic subsidy are optimal: Both a tariff and a subsidy increase price competition and while the former extracts foreign rents the latter results in quality upgrading. Third, there exists a rationale for a government to commit to a socially optimal policy to induce quality leadership by the domestic firm when cost asymmetries are low. Finally, we establish an equivalence result between the effects of long-run exchange rate changes and those of trade policy on price competition (but not on social welfare).     

Exact Skewness–Kurtosis Tests for Multivariate Normality and Goodness‐of‐Fit in Multivariate Regressions with Application to Asset Pricing Models*

We study the problem of testing the error distribution in a multivariate linear regression (MLR) model. The tests are functions of appropriately standardized multivariate least squares residuals whose distribution is invariant to the unknown cross‐equation error covariance matrix. Empirical multivariate skewness and kurtosis criteria are then compared with a simulation‐based estimate of their expected value under the hypothesized distribution. Special cases considered include testing multivariate normal and stable error distributions. In the Gaussian case, finite‐sample versions of the standard multivariate skewness and kurtosis tests are derived. To do this, we exploit simple, double and multi‐stage Monte Carlo test methods. For non‐Gaussian distribution families involving nuisance parameters, confidence sets are derived for the nuisance parameters and the error distribution. The tests are applied to an asset pricing model with observable risk‐free rates, using monthly returns on New York Stock Exchange (NYSE) portfolios over 5‐year subperiods from 1926 to 1995.     

How integrated is the world economy?

This paper develops a methodology to measure the degree of economic integration between nations that are members of an integrated area. We show that a fully integrated economic area (IEA) is characterized by three properties regarding the distribution of member shares of total IEA output and total IEA stocks of physical and human capital. We then show that the expected distribution of member shares within a fully IEA is a harmonic series, with the share distribution depending only on the number of IEA members. This property is then used to develop a composite indicator of the degree of economic integration within an IEA that indicates the distance between the theoretical and actual distribution of shares: the closer is the actual distribution to the expected distribution, the greater the degree of integration. We empirically compute our degree of integration for US states, and alternative regional trading agreements (e.g., EU countries, MERCOSUR, Bangkok Agreement, etc.) and a “world” comprising 64 countries.     

Are labels effective against child labor?

In this paper, we investigate the impact of introducing a label certifying the absence of child labor in the export production of the South. When most eligible producers in the South can obtain the label, its impact is considerably reduced by a displacement effect whereby adult workers replace children in the export sector while children replace adults in the domestic sector. The label is then unable to create a price differential in the South between goods produced under the label and those produced without it.When only a small fraction of eligible producers have access to the label, the South exports both labeled and unlabeled goods to the North. In this case, labeled producers generally gain while those without a label generally loose from the introduction of the label. Ex ante welfare may fall in the South if the probability of getting a label when one qualifies is small. The impact on child labor is in general ambiguous.     

Some robust exact results on sample autocorrelations and tests of randomness

Several exact results on the second moments of sample autocorrelations, for both Gaussian and non-Gaussian series, are presented. General formulae for the means, variances and covariances of sample autocorrelations are given for the case where the variables in a sequence are exchangeable. Bounds for the variances and covariances of sample autocorrelations from an arbitrary random sequence are derived. Exact and explicit formulae for the variances and covariances of sample autocorrelations from a Gaussian white noise are given. It is observed that the latter results hold for all spherically symmetric distributions. A simulation experiment, with Gaussian series, indicates that normalizing each sample autocorrelation with its exact mean and variance, instead of the usual approximate moments, can improve considerably the accuracy of the asymptotic N(0,1) distribution to obtain critical values for tests of randomness. The exact second moments of rank autocorrelations are also studied.     

Exact tests in single equation autoregressive distributed lag models

For hypotheses on the coefficient values of the lagged-dependent variables in the ARX class of dynamic regression models, test procedures are developed which yield exact inference for given (up to an unknown scale factor) distribution of the innovation errors. They include exact tests on the maximum lag length, for structural change and on the presence of (seasonal or multiple) unit roots, i.e. they cover situations where usually asymptotic and non-exact t, F, AOC, ADF or HEGY tests are employed. The various procedures are demonstrated and compared in illustrative empirical models and the approach is critically discussed.