Testing aggregation consistency across geography and commodities

Consistent aggregation of production data across commodities and Western USA states was tested using Lewbel's generalised composite commodity theorem. The applicability of the generalised composite commodity theorem for testing consistent geographic aggregation was demonstrated and applied to two groups of states. Consistent commodity aggregation was tested in each state for two output groups and three input groups and in one state for a larger number of groups. Most tests for commodity aggregation supported consistent aggregation of inputs but not outputs. Consistent geographic aggregation was supported for each output and input category across Pacific Northwest states but only for inputs across all Western states.Farm Management,

MARKET INTEGRATION TEST FOR PACIFIC EGG MARKETS

This paper uses of Johansen's multivariate cointegration test to test for egg market integration of six Pacific states, Washington, Idaho, Oregon, California, Nevada, and Arizona. We conclude that eggs from these states substitute for each other to some degree, and arbitrage possibilities through trade bind the egg prices. In addition, the Law of One Price (LOP), the case of perfect integration, is examined by testing the linear combination of cointegration vectors. Test results show that the LOP is not satisfied even though the egg markets in the six Pacific states are highly integrated. Arizona egg prices, California egg prices, and Washington egg prices play dominant roles on the Pacific egg market in the long run.Demand and Price Analysis, Livestock Production/Industries,

TESTING AGGREGATION CONSISTENCY ACROSS GEOGRAPHY AND COMMODITIES

Consistent aggregation of production data across commodities and states was tested using Lewbel's generalized composite commodity theorem (GCCT). This was the first empirical GCCT test for consistent geographic aggregation and was applied to two groups of states. Consistent commodity aggregation was tested in all states for two output groups and three input groups and in one state for a larger number of groups. Using a more powerful test procedure than previously applied to production data, most tests for commodity aggregation gave ambiguous results. Consistent geographic aggregation was generally supported across Pacific Northwest states but was ambiguous across all Western states. Key words: Aggregation, commodity, geographic, composite commodity theorem, multiple-comparison tests.Aggregation, commodity, geographic, composite commodity theorem, multiple-comparison tests., Research Methods/ Statistical Methods,

Diverse personalized recommendations with uncertainty from implicit preference data with the Bayesian Mallows Model

Clicking data, which exists in abundance and contains objective user preference information, is widely used to produce personalized recommendations in web-based applications. Current popular recommendation algorithms, typically based on matrix factorizations, often have high accuracy and achieve good clickthrough rates. However, diversity of the recommended items, which can greatly enhance user experiences, is often overlooked. Moreover, most algorithms do not produce interpretable uncertainty quantifications of the recommendations. In this work, we propose the Bayesian Mallows for Clicking Data (BMCD) method, which augments clicking data into compatible full ranking vectors by enforcing all the clicked items to be top-ranked. User preferences are learned using a Mallows ranking model. Bayesian inference leads to interpretable uncertainties of each individual recommendation, and we also propose a method to make personalized recommendations based on such uncertainties. With a simulation study and a real life data example, we demonstrate that compared to state-of-the-art matrix factorization, BMCD makes personalized recommendations with similar accuracy, while achieving much higher level of diversity, and producing interpretable and actionable uncertainty estimation.Comment: 27 page

Derived equivalences between generalized matrix algebras

summary:We construct derived equivalences between generalized matrix algebras. We record several corollaries. In particular, we show that the $n$-replicated algebras of two derived equivalent, finite-dimensional algebras are also derived equivalent