Ex Ante Price Commitment with Renegotiation in a Dynamic Market

This paper studies the endogenous determination of the price formation procedure in markets characterized by match-specific heterogeneity; such heterogeneity captures, for example, markets in which sellers own differentiated commodities and buyers have heterogeneous preferences. Specifically, we study a dynamic, stochastic model of a market in which, in each time period, agents on one side (e.g., sellers) strategically choose whether or not to "post", or commit themselves to, incomplete price contracts before they encounter agents of the opposite type. After a pair of agents of the opposite types have encountered each other, their match-specific values from trading with each other are realised. If no price contract was posted, then the terms of trade (and whether or not it occurs) are determined by bilateral negotiations. Otherwise, depending upon the agents� match-specific trading values and equilibrium continuation payoffs, trade occurs (if it does) either on the terms specified in the posted contract or at a renegotiated price (when renegotiation of the posted, incomplete price contract is mutually beneficial). We study the Markov subgame perfect equilibria of this market game, and address a variety of issues such as the impact of market frictions on the equilibrium proportion of trades that occur at a price specified in the ex-ante posted contract rather than at a price determined by ex-post bargaining.

MEASURING PROTECTION IN AGRICULTURE: THE PRODUCER SUBSIDY EQUIVALENT REVISITED

In the 1980s, the Producer Subsidy Equivalent (PSE) became the dominant measure of protection in applied studies of international agricultural trade. This paper analyzes potential biases in the ratio form of the PSE introduced by using actual domestic prices rather than social opportunity costs in the denominator. It is shown that doing so introduces a consistent under-estimation of the effects of trade restrictions and other price-support policies, relative to deficiency payments and other income-support policies. It is found that under plausible conditions this bias leads the PSE to rank protection levels across countries or crops incorrectly. In a sample of 250 activities across 33 countries, such errors were found to occur in 5% of crop comparisons and 8% of country comparisons, including a number of politically sensitive cases. An improved formula would therefore provide significantly more accurate results than the conventional PSE, with no additional data or more restrictive assumptions.Agricultural and Food Policy, International Relations/Trade,

Distortions to Agricultural Incentives in Senegal

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

Characterization of Saturn's bow shock: magnetic field observations of quasi-perpendicular shocks

Collisionless shocks vary drastically from terrestrial to astrophysical regimes resulting in radically different characteristics. This poses two complexities. First, separating the influences of these parameters on physical mechanisms such as energy dissipation. Second, correlating observations of shock waves over a wide range of each parameter, enough to span across different regimes. Investigating the latter has been restricted since the majority of studies on shocks at exotic regimes (such as supernova remnants) have been achieved either remotely or via simulations, but rarely by means of in situ observations. Here we present the parameter space of MA bow shock crossings from 2004 to 2014 as observed by the Cassini spacecraft. We find that Saturn's bow shock exhibits characteristics akin to both terrestrial and astrophysical regimes (MA of order 100), which is principally controlled by the upstream magnetic field strength. Moreover, we determined the θBn of each crossing to show that Saturn's (dayside) bow shock is predominantly quasi-perpendicular by virtue of the Parker spiral at 10 AU. Our results suggest a strong dependence on MA in controlling the onset of physical mechanisms in collisionless shocks, particularly nontime stationarity and variability. We anticipate that our comprehensive assessment will yield deeper insight into high MA collisionless shocks and provide a broader scope for understanding the structures and mechanisms of collisionless shocks

Deposit formation in hydrocarbon rocket fuels with an evaluation of a propane heat transfer correlation

A high pressure fuel coking testing apparatus was designed and developed and was used to evaluate thermal decomposition limits and carbon decomposition rates in heated copper tubes for hydrocarbon fuels. A commercial propane (90% grade) and chemically pure (CP) propane were tested. Heat transfer to supercritical propane was evaluated at 136 atm, bulk fluid velocities of 6 to 30 m/s, and tube wall temperatures in the range of 422 to 811 K. A forced convection heat transfer correlation developed in a previous test effort verified a prediction of most of the experimental data within a + or - 30% range, with good agreement for the CP propane data. No significant differences were apparent in the predictions derived from the correlation when the carbon resistance was included with the film resistance. A post-test scanning electron microprobe analysis indicated occurrences of migration and interdiffusion of copper into the carbon deposit

Distortions to Agricultural Incentives in Cameroon

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

THE VALUE OF QUALITY CERTIFICATION FOR INFANT FOODS: RESULTS FROM A MARKET EXPERIMENT IN MALI

This paper uses an experimental-economics technique to measure the potential impact of introducing quality certification to the market for infant foods in Mali, where malnutrition is widespread. We find that certification could substantially lower food costs, generating net economic benefits on the order of US$20 per infant, per year.Food Consumption/Nutrition/Food Safety,

Distortions to Agricultural Incentives in Sub-Saharan and North Africa

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

Distortions to Agricultural Incentives in Africa

Distorted incentives, agricultural and trade policy reforms, national agricultural development, Agricultural and Food Policy, International Relations/Trade, F13, F14, Q17, Q18,

Accelerating innovation with prize rewards: History and typology of technology prizes and a new contest design for innovation in African agriculture

"This paper describes how governments and philanthropic donors could drive innovation through a new kind of technology contest. We begin by reviewing the history of technology prizes, which operate alongside private intellectual property rights and public R&D to accelerate and guide productivity growth towards otherwise-neglected social goals. Proportional “prize rewards” would modify the traditional winner-take-all approach, by dividing available funds among multiple winners in proportion to measured achievement. This approach would provide a royalty-like payment for incremental success. The paper provides concludes with a specific example for how such prizes could be implemented to reward and help scale up successful innovations in African agriculture, through payments to innovators in proportion to the value created by their technologies after adoption. " from authors' abstractProductivity growth, Technology adoption, intellectual property, Agricultural R&D, Innovation,