This article evaluates the effects of a November 2004 phytosanitary rule that removed seasonal and geographic restrictions on the importation of fresh Hass avocados from approved orchards in Mexico to the United States. With the remaining systems approach compliance measures in place, pest risks do not substantially increase and U.S. net welfare rises by $77 million. Removal of remaining compliance measures may lead to lower net welfare gains depending on which measures are eliminated and the estimated probabilities of pest infestations. Copyright 2008, Oxford University Press.

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This paper presents support for long-run monetary neutrality based on evidence that individual time series for money, manufacturing prices, and agricultural prices are nonstationary but cointegrated, with a stationary proportional long-run relationship among their levels. Dynamic simulations from a vector error-correction model with this restriction imposed show that monetary shocks shift relative prices in favor of agriculture in the short run and permanently raise nominal prices. Manufacturing price shocks have similar long-run effects but initially place agriculture in a cost-price squeeze, while agricultural price shocks are transitory and have little impact on the other series.

Pointed pseudo-triangulations are planar minimally rigid graphs embedded in the plane with pointed vertices (incident to an angle larger than π). In this paper we prove that the opposite statement is also true, namely that planar minimally rigid graphs always admit pointed embeddings, even under certain natural topological and combinatorial constraints. The proofs yield efficient embedding algorithms. They also provide-to the best of our knowledge-the first algorithmically effective result on graph embeddings with oriented matroid constraints other than convexity of faces.