relaxations of approximate linear programs for the real option management of commodity storage the real option management of commodity conversion assets gives rise to intractable markov decision processes mdps in part because of the use of high dimensional models of commodity forward curve evolution as commonly done in practice focusing on commodity storage we identify a deficiency of approximate linear programming alp which we address by developing a novel approach to derive relaxations of approximate linear programs we apply our approach to obtain a class of tractable alp relaxations also subsuming an existing method we provide theoretical support for the use of these alp relaxations rather than their associated approximate linear programs applied to existing natural gas storage instances our alp relaxations significantly outperform their corresponding approximate linear programs our best alp relaxation is both near optimal and competitive with albeit slower than state of the art methods for computing heuristic policies and lower bounds on the value of commodity storage but is m

50th anniversary article option pricing valuation models and applications this paper surveys the literature on option pricing from its origins to the present an extensive review of valuation methods for european and american style claims is provided applications to complex securities and numerical methods are surveyed emphasis is placed on recent trends and developments in methodology and modeling

effective sub simulation free upper bounds for the monte carlo pricing of callable derivatives and various improvements to existing methodologies abstract we present a new non nested approach for computing additive upper bounds for callable derivatives using monte carlo simulation it relies on the regression of greeks computed using adjoint methods we also show that it is possible to early terminate paths once points of optimal exercise have been reached a natural control variate for the multiplicative upper bound is introduced which renders it competitive to the additive one in addition a new bi iterative family of upper bounds is introduced which takes a stopping time an upper bound and a martingale as inputs

nutrition and labor producvivity in agriculture estimates for rural south india using panel data for rural south india a fixed effects individual wage equation and farm production function are estimated that have calorie intake and nutritional status weight for height of workers as their arguments neither market wages nor farm output are observed to be responsive to changes in the daily energy intake of workers however both are highly elastic with respect to weight for height these results suggest that while the human body can adapt to inadequate nutrition in the short run it cannot adapt as readily to chronic malnutrition that eventually results in loss of weight for height copyright 1988 by mit press

beyond the silicon valley university r d and high technology location abstract in this paper we examine high technology location in us counties focusing on the relationship with university research and development r d the dirichlet multinomial model an extension of the conditional logit model that allows for overdispersion is used to estimate the determinants of manufacturing establishment births in us counties we test the hypothesis that university r d generates spillovers captured locally as new high technology establishments after controlling for local costs demand agglomeration economies and other important location factors estimates show that r d expenditures at universities exert a positive statistically significant influence on the decision to locate plants in a county the marginal impacts of increased r d funding on county probabilities for new high tech plant births however appear to be modest separate estimates indicate that the findings hold up across most individual high tech industries our model also determines the distance from university r d in which economic spillovers can be detected spillover effects may extend up to approximately 145 miles from universities

health shocks and natural resource management evidence from western kenya poverty and altered planning horizons brought on by the hiv aids epidemic can change individual discount rates altering incentives to conserve natural resources using longitudinal household survey data from western kenya we estimate the effects of health status on investments in soil quality as indicated by households agricultural land fallowing decisions we first show that this effect is theoretically ambiguous while health improvements lower discount rates and thus increase incentives to conserve natural resources they also increase labor productivity and make it more likely that households can engage in labor intensive resource extraction activities we find that household size and composition are predictors of whether the effect of health improvements on discount rates dominates the productivity effect or vice versa since households with more and younger members are better able to reallocate labor to cope with productivity shocks the discount rate effect dominates for these households and health improvements lead to greater levels of conservation in smaller families with less substitutable labor the productivity effect dominates and health improvements lead to greater environmental degradation

the labour market impact of body weight in china a semiparametric analysis while a positive wage effect of body mass index bmi is widely observed in low income developing countries a negative wage effect of bmi is often observed in high income developed countries to fill the gap between these previous findings we investigate the relationship between body weight and wages in transition economies we focus on china whose rapid economic growth of the 1990s was followed by a rapid increase in overweight and obesity while still experiencing significant food insecurity and underweight we first use several parametric regression strategies to obtain a consistent estimate of the wage effects of weight second we adopt a semiparametric partially linear model that allows for endogeneity of weight parametric regressions provide mixed results and the sign and magnitude of their estimates are sensitive to the choice of samples and regression strategies semiparametric estimates provide evidence of a wage penalty for very heavy and thin persons among both men and women the wage pena

re evaluating the impact of immigration on the u s rental housing market abstract previous studies provide evidence that immigration increases housing prices and rents to deal with endogenous location choices of immigrants these studies often use a shift share instrumental variable approach this approach however fails to adequately account for the natural attraction of immigrants to cities with thriving economies high immigration cities provide more economic opportunities and thus exhibit persistently rising housing prices and rents this paper improves upon the traditional empirical approach by explicitly controlling for initial city characteristics that lead to both increases in immigration and the evolution of rents results suggest that after controlling for endogenous sorting of immigrants the positive effect of immigration on rents is attenuated while the impact of immigrant inflows is smaller an extension of the main results suggests the effects of immigration on rents remains larger than that of native inflows

pricing american style securities using simulation abstract we develop a simulation algorithm for estimating the prices of american style securities i e securities with opportunities for early exercise our algorithm provides both point estimates and error bounds for the true security price it generates two estimates one biased high and one biased low both asymptotically unbiased and converging to the true price combining the two estimators yields a confidence interval for the true price the proposed algorithm is especially attractive compared with lattice and finite difference methods when there are multiple state variables and a small number of exercise opportunities preliminary computational evidence is given

convergence from discrete to continuous time contingent claims prices this article generalizes the cox ross and rubinstein 1979 binomial option pricing model and establishes a convergence from discrete time multivariate multinomial models to continuous time multidimensional diffusion models for contigent claims prices the key to the approach is to approximate the n dimensional diffusion price process by a sequence of n variate n 1 nomial processes it is shown that contingent claims prices and dynamic replicating portfolio strategies derived from the discrete time models converge to their corresponding continuous time limits article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

a stochastic control approach to manage operational risk in power systems in this paper the novel method operational risk managing optimal power flow ormopf for minimizing the expected cost of power system operation is proposed in contrast to previous research in the area the proposed method does not use a security criterion instead the expected cost of operation includes expected costs of system failures this will lead to more flexible operating limits giving a more adequate balance between risk and economic benefit of transmission the method assumes a set of observable system variables such as transfers through specific transmission corridors system frequency or distance to a bifurcation surface then impulse control is applied to find an optimal strategy for activation of tertiary reserves based on the values of the observables

practical policy iteration generic methods for obtaining rapid and tight bounds for bermudan exotic derivatives using monte carlo simulation abstract we introduce a set of improvements which allow the calculation of very tight lower bounds for bermudan derivatives using monte carlo simulation these tight lower bounds can be computed quickly and with minimal hand crafting our focus is on accelerating policy iteration to the point where it can be used in similar computation times to the basic least squares approach but in doing so introduce a number of improvements which can be applied to both the least squares approach and the calculation of upper bounds using the andersen broadie method the enhancements to the least squares method improve both accuracy and efficiency results are provided for the displaced diffusion libor market model demonstrating that our practical policy iteration algorithm can be used to obtain tight lower bounds for cancellable cms steepener snowball and vanilla swaps in similar times to the basic least squares method

pricing and exercising american options an asymptotic expansion approach abstract this paper proposes and implements a novel asymptotic expansion approach for pricing discretely monitored american options and approximating their optimal early exercise boundaries under a generic class of multivariate derivative pricing models incorporating both stochastic volatility and levy driven jumps in asset return the price and the critical value can be expanded up to any arbitrary order around those under a simple constant volatility jump diffusion model the expansion terms are then efficiently implemented by exactly solving some backward inductions via closed form fourier transforms where a substantial extension of the hilbert transform method of feng and linetsky 2008a 2009 plays an important role the efficiency of our method is illustrated through some representative examples as applications we analyze the impacts of various model parameters on the optimal early exercise boundary compare the optimal early exercise boundaries under different models and propose a derivative proxy based method for practically exercising american options under models with stochastic volatility and jumps

extending quadrature methods to value multi asset and complex path dependent options abstract the exposition of the quadrature quad method andricopoulos widdicks duck and newton 2003 universal option valuation using quadrature methods journal of financial economics 67 447 471 see also corrigendum journal of financial economics 73 603 2004 is significantly extended to cover notably more complex and difficult problems in option valuations involving one or more underlyings trials comparing several techniques in the literature adapted from standard lattice grid and monte carlo methods to tackle particular types of problem show that quad offers far greater flexibility superior convergence and hence increased accuracy and considerably reduced computational times the speed advantage of quad means that even under the curse of dimensionality it is not necessary to resort to monte carlo methods certainly for options involving up to five underlying assets given the universality and flexibility of the method it should be the method of choice for pricing options involving multiple underlying assets in the presence of many features such as early exercise or path dependency

convergence and biases of monte carlo estimates of american option prices using a parametric exercise rule abstract this paper presents an algorithm for pricing american options using monte carlo simulation the method is based on using a parametric representation of the early exercise decision it is shown that as long as this parametric representation subsumes all relevant stopping times error bounds can be constructed using two different estimates one which is biased low and one which is biased high both are consistent and asymptotically unbiased estimators of the true option value results for high dimensional american options confirm the viability of the numerical procedure the convergence results of the paper shed light into the biases present in other algorithms proposed in the literature

caste discrimination and transaction costs in the labor market evidence from rural north india abstract this paper is an empirical attempt to quantify caste based discrimination in the labor market using household data taken from rural north india in the regression analysis transaction costs associated with entry into the labor market and reservation wages are estimated simultaneously along with market wages the estimation results provide evidence of the existence of transaction costs in the labor market and discrimination against backward classes with regard to access to regular employment in line with previous studies the results suggest that the achievements of india s reservation policy so far have at best been limited in addition a comparison between the estimates from the model employed in this paper and conventional reduced form approaches shows that discrimination in labor market entry is likely to be underestimated in the conventional reduced form approaches

american options under stochastic volatility the problem of pricing an american option written on an underlying asset with constant price volatility has been studied extensively in literature real world data however demonstrate that volatility is not constant and stochastic volatility models are used to account for dynamic volatility changes option pricing methods that have been developed in literature for pricing under stochastic volatility focus mostly on european options we consider the problem of pricing american options under stochastic volatility which has had relatively much less attention from literature first we develop a transformation procedure to compute the optimal exercise policy and option price and provide theoretical guarantees for convergence second using this computational tool we explore a variety of questions that seek insights into the dependence of option prices exercise policies and implied volatilities on the market price of volatility risk and correlation between the asset and stochastic volatility the speed and accuracy of the procedure are compared against existing methods as well

occupational variation in quantity quality trade off in a brawn based economy the paper revisits the theory of the quantity quality trade off and demonstrates that the relationship between quantity and health of children is subject to occupational variation in physical energ

dynamic portfolio optimization with transaction costs heuristics and dual bounds we consider the problem of dynamic portfolio optimization in a discrete time finite horizon setting our general model considers risk aversion portfolio constraints e g no short positions return predictability and transaction costs this problem is naturally formulated as a stochastic dynamic program unfortunately with nonzero transaction costs the dimension of the state space is at least as large as the number of assets and the problem is very difficult to solve with more than one or two assets in this paper we consider several easy to compute heuristic trading strategies that are based on optimizing simpler models we complement these heuristics with upper bounds on the performance with an optimal trading strategy these bounds are based on the dual approach developed in brown et al brown d b j e smith p sun 2009 information relaxations and duality in stochastic dynamic programs oper res 58 4 785 801 in this context these bounds are given by considering an investor who has access to perfect information about future returns but is penalized for using this advance information these heuristic strategies and bounds can be evaluated using monte carlo simulation we evaluate these heuristics and bounds in numerical experiments with a risk free asset and 3 or 10 risky assets in many cases the performance of the heuristic strategy is very close to the upper bound indicating that the heuristic strategies are very nearly optimal this paper was accepted by dimitris bertsimas optimization

american option sensitivities estimation via a generalized infinitesimal perturbation analysis approach in this paper we develop efficient monte carlo methods for estimating american option sensitivities the problem can be reformulated as how to perform sensitivity analysis for a stochastic optimization problem with model uncertainty we introduce a generalized infinitesimal perturbation analysis ipa approach to resolve the difficulty caused by discontinuity of the optimal decision with respect to the underlying parameter the ipa estimators are unbiased if the optimal decisions are explicitly known to quantify the estimation bias caused by intractable exercising policies in the case of pricing american options we also provide an approximation guarantee that relates the sensitivity under the optimal exercise policy to that computed under a suboptimal policy the price sensitivity estimators yielded from this approach demonstrate significant advantages numerically in both high dimensional environments and various process settings we can easily embed them into many of the most popular pricing algorithm

primal dual simulation algorithm for pricing multidimensional american options this paper describes a practical algorithm based on monte carlo simulation for the pricing of multidimensional american i e continuously exercisable and bermudan i e discretely exercisable

the university in the metropolitan arena impacts and public policy implications this paper estimates some of the impacts associated with a metropolitan university the impact of the university in the metropolitan arena is conceptualised as a series of backward expenditure and forward knowledge related linkages these relationships can be both positive and negative and can operate in both the short and long terms their correct identification requires that the counter factual situation of the area without the university be adequately specified on the basis of a case study of the impacts associated with northwestern university on the chicago metropolitan area some of these issues are highlighted the results emphasise the magnitude of the university expenditure links with the metropolitan economy and the importance of scale when comparing these with more localised negative impacts the paper concludes with some public policy implications relating to the role of the university as a non profit organisation competing with local businesses and as an export base sector in the metropol

the effects of colleges and universities on local labor markets there is little systematic evidence documenting a relationship between colleges and universities and local economies using census data for 218 smsas this paper examines the relationship between various measures of university quality and local labor market conditions the authors find that area employment growth rates and the percentage of the work force employed as scientists and engineers are positively and significantly related to measures of university quality however the data can not reject the hypothesis that university quality has no significant effect on area income the employment rate net migration rates or even the share of employment in high tech industries copyright 1993 by mit press

income productivity in china on the role of health this study provides empirical evidence regarding the income productivity of health human capital in china we appeal to concepts from human capital theory to support a basic model that treats health as a form of human capital in the income production process our model examines the economic return at the household level from the health of its individual members we estimate this with a longitudinal sample drawn from the china health and nutrition survey chns allowing us to exploit within variation in health and income to address possible unobservables biasing estimates of the impact of health on income in the simple cross sectional setting household income is strongly influenced by the health of its members particularly in rural areas these findings could have important implications for health and economic policy making aimed at reducing the long standing urban rural economic gap and more comprehensively insuring the rural population against health and economic risk

closed form solutions for term structure derivatives with log normal interest rates we derive a unified model that gives closed form solutions for caps and floors written on interest rates as well as puts and calls written on zero coupon bonds the crucial assumption is that simple interest rates over a fixed finite period that matches the contract which we want to price are log normally distributed moreover this assumption is shown to be consistent with the heath jarrow morton model for a specific choice of volatility closed form solutions for interest rate derivatives in particular caps floors and bond options have been obtained by a number of authors for markovian term structure models with normally distributed interest rates or alternatively log normally distributed bond prices see for example jamshidian 1989 1991a heath jarrow and morton 1992 brace and musiela 1994 geman el karoui and rochet 1995 these models support black scholes type formulas most frequently used by practitioners for pricing bond options and swaptions unfortunately these models imply negative interest rates with positive probabilities and hence they are not arbitrage free in an economy with opportunities for riskless and costless storage of money briys crouhy and schobel 1991 apply the gaussian framework to derive closed form solutions for caps floors and european zero coupon bond options to exclude the influence of negative forward rates on the pricing of zero coupon bond options they introduce an additional boundary condition as shown by rady and sandmann 1994 these pricing formulas are only supported by a term structure model with an absorbing boundary for the forward rate at zero where the absorbing probability is not negligible which for a term structure model is a quite problematic assumption

numerical evaluation of multivariate contingent claims we develop a numerical approximation method for valuing multivariate contingent claims the approach is based on an n dimensional extension of the lattice binomial method closed form solutions for the jump probabilities and the jump amplitudes are obtained the accuracy of the method is illustrated in the case of european options when there are three underlying assets article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

a lattice framework for option pricing with two state variables a procedure is developed for the valuation of options when there are two underlying state variables the approach involves an extension of the lattice binomial approach developed by cox ross and rubinstein to value options on a single asset details are given on how the jump probabilities and jump amplitudes may be obtained when there are two state variables this procedure can be used to price any contingent claim whose payoff is a piece wise linear function of two underlying state variables provided these two variables have a bivariate lognormal distribution the accuracy of the method is illustrated by valuing options on the maximum and minimum of two assets and comparing the results for cases in which an exact solution has been obtained for european options one advantage of the lattice approach is that it handles the early exercise feature of american options in addition it should be possible to use this approach to value a number of financial instruments that have been created in recent years

numerical valuation of high dimensional multivariate american securities we consider the problem of pricing an american contingent claim whose payoff depends on several sources of uncertainty several efficient numerical lattice based techniques exist for pricing american securities depending on one or few up to three risk sources however these methods cannot be used for high dimensional problems since their memory requirement is exponential in the number of risk sources we present an efficient numerical technique that combines monte carlo simulation with a particular partitioning method of the underlying assets space which we call stratified state aggregation ssa using this technique we can compute accurate approximations of prices of american securities with an arbitrary number of underlying assets our numerical experiments show that the method is practical for pricing american claims depending on up to 400 risk sources