Package Sizes, Tariffs, Quantity Discount and Premium

We analyze nonlinear pricing problem under monopoly using two hidden types of agents with linear demands and fully characterize all possible optimal solutions for both ordered and non-ordered demands. We show that both optimal packages can either contain Pareto-efficient quantities or one package can be undersized or oversized. All these effects are non- degenerate and are expected to hold for nonlinear demands. Surprisingly, the total output under nonlinear price discrimination with self- selection is neither unambigously realted to efficiency nor to the degree of monopoly power (demand elasticity). We also show that under limited range of parameters quantity premia can occur only when demands are ordered.Principal-agent, self-selection, nonlinear pricing, package pricing, Pareto efficiency

Informational Structure and Effciency in Monopoly

The paper focuses on efficiency under monopoly. Contrary to common wisdom, nine examples given in the paper show that a Pareto-efficient output in monopoly is possible under both linear and nonlinear pricing. Pareto efficiency can be achieved when consumers are homogeneous as well as heterogeneous. Since Pareo-efficiency is possible under different demand and cost conditions; different pricing strategies; and different degree of consumer heterogeneity, in general, monopoly per se is not the cause for ineficiency.Monopoly, Pareto Efficiency

All solution graphs in multidimensional screening

We study general discrete-types multidimensional screening without any noticeable restrictions on valuations, using instead epsilon-relaxation of the incentive-compatibility constraints. Any active (becoming equality) constraint can be perceived as "envy" arc from one type to another, so the set of active constraints is a digraph. We find that: (1) any solution has an in-rooted acyclic graph ("river"); (2) for any logically feasible river there exists a screening problem resulting in such river. Using these results, any solution is characterized both through its spanning-tree and through its Lagrange multipliers, that can help in finding solutions and their efficiency/distortion properties.incentive compatibility; multidimensional screening; second-degree price discrimination; non-linear pricing; graphs

Facile Synthesis of Activated Carbon from Cellulose in the Presence of Air for Ammonia Recovery in Resource-Constrained Settings

As efforts to provide sanitation services in low-resource rural settings of the world proliferate, nutrient recovery via source separation of urine becomes important for economic and environmental implications in these regions of challenging socio-economic constraints. Substantial N (in some cases > 50%) is lost from urine via off-gassed ammonia which can be captured and utilized more efficiently by the use of sorbents such as activated carbon synthesized locally in resource-constrained settings. My work is focused on developing a simple method to synthesize functionalized-activated carbon from locally available biomass at moderate temperatures (400-450)°C in the presence of air. Using cellulose as a model biomass and diammonium hydrogenphosphate (DAP) as the activating agent, the production of activated carbon is explored in a simple semi-batch Partial Oxidation (POX) reactor setup. DAP helps to facilitate low temperature pyrolysis of cellulose by the action of phosphoric acid which helps in depolymerization and the breakdown of glycosidic linkages present in lignocellulosic biomass. Further, the film of condensed phosphates prevents carbon oxidation at high temperature in the presence of air. This study provides insight into the interaction between DAP and biomass, as well as the char forming mechanism. Various characterization techniques such as N2 physisorption, XPS, DRIFTS, SEM, TEM, surface charge measurements and Raman spectroscopy are utilized to compare the properties between activated carbon formed under nitrogen and partial oxidative conditions. The interaction of DAP with cellulose is investigated and the nature of bonding of the heteroatoms to the carbonaceous matrix is elucidated. Our results indicate that the quality of activated carbon prepared under partial oxidation condition is comparable to carbon prepared under nitrogen, leading to the possibility of an activated biochar production scheme on a small scale. The prepared activated carbon is utilized to recover ammonia off-gassed from urine providing multiple benefits including odor removal and nutrient recovery since ammonia augmented biochar can serve as a soil amendment. The hygroscopic nature of the prepared activated biochar is useful for holding soil moisture during the dry season and is envisioned to provide better soil health for round the year crop production. The efficacy of the synthesized activated biochar as an ammonia adsorbent is evaluated from adsorption isotherms by studying equilibrium capacity and elucidating the nature of the interaction by Temperature Programmed Desorption (TPD) and DRIFTS measurements. Our results show promising capacities for ammonia adsorption from the gas phase. The total dry ammonia adsorption capacity of the synthesized activated carbons was found to be ~ (24-28) mg/g at 50°C, comparable in magnitude to zeolites. It was observed that > 90% of the adsorbed ammonia could be easily recovered by simple water washing at room temperature, facilitating facile regeneration.PHDChemical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/146068/1/mnahata_1.pd

Equilibrium structures in vertical oligopoly

The central purpose of this paper is to examine vertical integration as an equilibrium phenomenon. We model it as integration between Cournot oligopolists in both the upstream and the downstream stages. We consider the issue of private profitability versus collective profitability and show that under several situations the equilibrium outcomes may result in a Prisoner's dilemma. The analysis is extended to consider equilibrium outcomes in a dynamic setting, where we find no integration to be a relatively common outcome.

An application of Ramsey model in transition economy: a Russian case study

This case study uses the Ramsey model to analyze whether the current electricity prices charged by the natural monopoly Novosibirskenergo in a major industrial region of the Russian Federation are socially optimal. Our estimates of demand elasticities for two major groups of consumers, namely households and industrial users, show that prices are not socially optimal. A decrease in price for industrial users and an increase in price for households would bring the prices closer to socially optimal.Natural monopolies; Transition economy; Ramsey model.

COMPARATIVE ANALYSIS OF MODULATION SCHEMES USING ADAPTIVE EQUALIZATION AS FADING MITIGATION TECHNIQUE

Inter-symbol interference (ISI) due to multipath fading is a vital problem in high-speed wireless communication which restricts communication quality and capacity. Therefore, in addition to choosing a fading mitigation technique, it is also important to strategically select a modulation scheme for effective data transmission. Recent literature review on wireless standards, such as 3G and 4G indicates that QAM and QPSK are suitable choices for data transmission. In this paper, a comparative analysis on selected modulation schemes is performed in a fading environment. The mitigation of fading is done using adaptive equalization technique. Also, we show that the signal to noise ratio (SNR) is an important parameter to choose. It is observed that, even when an adaptive equalizer is used at the receiver, a very low SNR gives very high symbol error rate (SER). We derive some important conclusions from our simulation result: QPSK shows minimum SER, whereas 256-PSK and 256-PAM perform worse. Given its spectral efficiency and a low SER, the best choice is 256- QAM