small transaction cost asymptotics and dynamic hedging abstract transaction costs are one of the major impediments to the implementation of dynamic hedging strategies we consider an alternative to utility maximization similar to the good deal pricing framework in incomplete markets we perform a dynamic risk reward analysis for a family of non self financing strategies of practical importance deterministic time hedging i e hedging at predetermined fixed times in the limit of small relative transaction costs we carry out the asymptotic analysis and find that transaction costs affect the hedge ratios and that the time between trades is related in a simple way to the local sensitivities of the replication target

determinacy and identification with taylor rules the new keynesian taylor rule theory of inflation determination relies on explosive dynamics by raising interest rates in response to inflation the fed induces ever larger inflation unless inflation jumps to one particular value on each date however economics does not rule out explosive inflation so inflation remains indeterminate attempts to fix this problem assume that the government will choose to blow up the economy if alternative equilibria emerge by following policies we usually consider impossible the taylor rule is not identified without unrealistic assumptions thus taylor rule regressions do not show that the fed moved from passive to active policy in 1980

on the mean variance tradeoff in option replication with transactions costs this paper analyzes the tradeoff between cost and risk of discretely rebalanced option hedges in the presence of transactions costs i present closed form solutions for expected hedging error transactions costs and variance of the cash flow from a time based hedging strategy similar to that analyzed by leland 1985 furthermore i characterize the cost and risk of a move based hedging strategy without resorting to monte carlo simulations all results are sufficiently general to accommodate the use of a transactions costs adjusted hedging volatility and an asset rate of return that differs from the risk free rate of return

option replication in discrete time with transaction costs option replication is discussed in a discrete time framework with transaction costs the model represents an extension of the cox ross rubinstein binomial option pricing model to cover the case of proportional transaction costs the method proceeds by constructing the appropriate replicating portfolio at each trading interval numerical values of these prices are presented for a range of parameter values the paper derives a simple black scholes type approximation for the option prices with transaction costs and demonstrates numerically that it is quite accurate for plausible parameter values

financial innovation and the transactions demand for cash we document cash management patterns for households that are at odds with the predictions of deterministic inventory models that abstract from precautionary motives we extend the baumol tobin cash inventory model to a dynamic environment that allows for the possibility of withdrawing cash at random times at a low cost this modification introduces a precautionary motive for holding cash and naturally captures developments in withdrawal technology such as the increasing diffusion of bank branches and atm terminals we characterize the solution of the model which qualitatively reproduces several empirical patterns we estimate the structural parameters using micro data and show that quantitatively the model captures important economic patterns the estimates are used to quantify the expenditure and interest rate elasticity of money demand the impact of financial innovation on money demand the welfare cost of inflation and the benefit of atm ownership

when does a central bank s balance sheet require fiscal support abstract using a simple general equilibrium model we argue that it would be appropriate for a central bank with a large balance sheet composed of long duration nominal assets to have access to and be willing to ask for support for its balance sheet by the fiscal authority otherwise its ability to control inflation may be at risk this need for balance sheet support a within government transaction is distinct from the need for fiscal backing of inflation policy that arises even in models where the central bank s balance sheet is merged with that of the rest of the government

the effects of transaction costs and different borrowing and lending rates on the option pricing model a note this paper modifies the black scholes option pricing model to include the effects of transaction costs and different borrowing and lending rates the paper demonstrates that these market imperfections tend to offset each other yielding a bounded range of prices for each option the paper also shows that under some conditions the option pricing hedge may be society s lowest cost financial intermediary

a simple formula for the expected rate of return of an option over a finite holding period under conditions consistent with the black scholes formula a simple formula is developed for the expected rate of return of an option over a finite holding period possibly less than the time to expiration of the option under these conditions surprisingly the expected future value of a european option even prior to expiration is shown equal to the current black scholes value of the option except that the expected future value of the stock at the end of the holding period replaces the current stock price in the black scholes formula and the future value of a riskless invesment of the striking price replaces the striking price an extension of this result is used to approximate moments of the distribution of returns from an option portfolio

optimal delta hedging under transactions costs this paper examines the problem of delta hedging portfolios of options under transactions costs by maximising expected utility or minimising a loss function on the replication error we extend the work of hodges and neuberger 1989 to study the optimal strategy under a general cost function with fixed and proportional costs a computational procedure for solving this problem is described and we develop an efficient computational method for the case of proportional transaction costs we examine the nature of the solution close to the expiry date and using simulation we compare the performance of the optimal strategies with other common strategies

spring cleaning rural water impacts valuation and property rights institutions the brief summarizes the spring cleaning rural water impacts valuation and property rights institutions the first two rounds of spring protection occurred in january april 2005 and august november 2005 the author measure health impacts of spring protection an investment that improves source water quality the author also estimate households valuation of spring protection and simulate the welfare impacts of alternatives to the current system of common property rights in water which limits incentives for private investment spring infrastructure investments reduce fecal contamination by 66 percent but household water quality improves less due to recontamination child diarrhea falls by one quarter travel cost based revealed preference estimates of households valuations are much smaller than both stated preference valuations and health planners valuations and are consistent with models in which the demand for health is highly income elastic the author estimate that private property norms would generate little additional investment while imposing large static costs due to above marginal cost pricing private property will function better at higher income levels or underwater scarcity and alternative institutions could yield pareto improvements

rethinking the economics of water an assessment water is rising on the policy agenda as population growth and climate change intensify scarcity shocks and access inequalities the conventional economic policy recommendations privatization pricing and property rights have struggled due to a failure to account adequately for the politics of water and the associated distributional conflicts we identify distinctive social and physical characteristics of water supply and demand and explore their implications for three central areas of water policy financing infrastructure pricing and property rights reform growing dependence on groundwater and non networked water supplies exacerbates these challenges and reinforces the need to rethink the economics of water and tackle the political challenges head on meeting the water sustainable development goals would require institutional and technological innovations to supply allocate and manage water as well as a sustained political and financial commitment to address those who might be left behind

effectiveness of cppi strategies under discrete time trading abstract the paper analyzes the effectiveness of the constant proportion portfolio insurance cppi method under trading restrictions if the cppi method is applied in continuous time the cppi strategies provide a value above a floor level unless the price dynamics of the risky asset permit jumps the risk of violating the floor protection is called gap risk in practice it is caused by liquidity constraints and price jumps both can be modelled in a setup where the price dynamics of the risky asset are described by a continuous time stochastic process but trading is restricted to discrete time we propose a discrete time version of the continuous time cppi strategies which satisfies three conditions the resulting strategies are self financing the asset exposure is non negative and the value process converges we determine risk measures such as the shortfall probability and the expected shortfall and discuss criteria which ensure that the gap risk does not increase to a level which contradicts the original intention of portfolio insurance in addition we introduce proportional transaction costs and analyze their effects on the risk profile

comment on a probability based stress test of federal reserve assets and income by jens h e christensen jose a lopez and glenn d rudebusch

extensive margins and the demand for money at low interest rates we argue that the relevant monetary decision for the majority of u s households is not the fraction of assets to be held in interest bearing form but whether to hold any such assets at all we call this the decision to adopt the financial technology we show that the key variable governing the adoption decision is the product of the interest rate times the total amount of assets this implies that the interest elasticity of household money demand at low interest rates can be estimated from the variation in asset holdings in a cross section of households rather than historical interest rate variations we do so with the 1989 survey of consumer finances we find that a the elasticity of money demand is very small when the interest rate is small b the probability that a household holds any amount of interest bearing assets is positively related to the level of financial assets and c the cost of adopting financial technologies is negatively related to participation in a pension program at intere

the mystique surrounding the central bank s balance sheet applied to the european crisis abstract a central bank s resource constraint bounds the dividends it can distribute by the present value of seignorage which is a modest share of gdp this is in spite of the mystique behind a central bank s balance sheet moreover the statutes of the federal reserve or the ecb make it difficult for it to redistribute resources across regions in a simple model of sovereign default where multiple equilibria arise if debt repudiation lowers fiscal surpluses the central bank may help to select one equilibrium the central bank s main lever over fundamentals is to raise inflation but otherwise the balance sheet gives it little leeway

fiscal requirements for price stability maintaining price stability requires not only commitment to an appropriate monetary policy rule but an appropriate scal policy rule as well ricardian equivalence does not imply that scal policy is irrelevant except in the case of a certain class of policies ricardian policies the role of scal developments in inflation determination under a non ricardian regime is illustrated through an analysis of the bond price support regime of the 1940s a monetary scal regime with attractive properties would combine a taylor rule for monetary policy with nominal decit targeting as a scal policy commitment

rethinking the economics of rural water in africa rural africa lags behind global progress to provide safe drinking water to everyone decades of effort and billions of dollars of investment have yielded modest gains with high but avoidable health and economic costs borne by over 300m people lacking basic water access we explore why rural water is different for communities schools and healthcare facilities across characteristics of scale institutions demand and finance the findings conclude with policy recommendations to i network rural services at scale ii unlock rural payments by creating value and iii design and test performance based funding models at national and regional scales with an ambition to eliminate the need for future sustainable development goals

tractable hedging an implementation of robust hedging strategies abstract this paper analyzes tractable robust hedging strategies in diffusion type models including stochastic volatility models a robust hedging strategy avoids any losses as long as volatility stays within a given interval it does not depend on the exact specification of the volatility process and therefore mitigates problems caused by model misspecification a tractable hedging strategy is defined as the sum over black scholes strategies for a convex concave payoff the cheapest robust hedge is given by a bs hedge at the upper lower volatility bound thus it is tractable for all other payoffs one has to solve a black scholes barenblatt equation and the cheapest robust hedge is not tractable a tractable hedge can then be found by decomposing the payoff into a convex and a concave function each of which is hedged separately we first give the decomposition that minimizes the initial capital second we show that it may be even cheaper to hedge a dominating payoff and we show explicitly how to determine the optimal dominating payoff we illustrate our results by two examples

the perils of taylor rules abstract since john taylor s 1993 carnegie rochester conf ser publ policy39 195 214 seminal paper a large literature has argued that active interest rate feedback rules that is rules that respond to increases in inflation with a more than one for one increase in the nominal interest rate are stabilizing in this paper we argue that once the zero bound on nominal interest rates is taken into account active interest rate feedback rules can easily lead to unexpected consequences specifically we show that even if the steady state at which monetary policy is active is locally the unique equilibrium typically there exist an infinite number of equilibrium trajectories originating arbitrarily close to that steady state that converge to a liquidity trap that is a steady state in which the nominal interest rate is near zero and inflation is possibly negative journal of economic literature classification numbers e52 e31 e63

an analysis of the risk in discretely rebalanced option hedges and delta based techniques the stochastic properties of discretely rebalanced option hedges have been studied extensively beginning with black and scholes 1973 in each analysis hedges were delta neutral after rebalancing we argue that the distributional properties of discretely rebalanced hedges are such that delta based hedging is not the variance minimizing strategy this paper obtains analytical expressions for the variance minimizing option hedge ratios we also evaluate the hedge variance to assess the magnitude of the variance reduction over delta based hedges for representative parameter values we show that systematic departures from delta based hedges can yield significant reductions in hedge variance even for one day rebalancing intervals

option pricing and replication with transactions costs transactions costs invalidate the black scholes arbitrage argument for option pricing since continuous revision implies infinite trading discrete revision using black scholes deltas generates errors which are correlated with the market and do not approach zero with more frequent revision when transactions costs are included this paper develops a modified option replicating strategy which depends on the size of transactions costs and the frequency of revision hedging errors are uncorrelated with the market and approach zero with more frequent revision the technique permits calculation of the transactions costs of option replication and provides bounds on option prices

inflation expectations and risk premiums in an arbitrage free model of nominal and real bond yields differences between yields on comparable maturity u s treasury nominal and real debt the so called breakeven inflation bei rates are widely used indicators of inflation expectations however better measures of inflation expectations could be obtained by subtracting inflation risk premiums from the bei rates we provide such decompositions using an estimated affine arbitrage free model of the term structure that captures the pricing of both nominal and real treasury securities our empirical results suggest that long term inflation expectations have been well anchored over the past few years and inflation risk premiums although volatile have been close to zero on average

optimal replication of options with transactions costs and trading restrictions this paper analyzes the strategy that minimizes the initial cost of replicating a contingent claim in a market with transactions costs and trading constraints the linear programming and two stage backward recursive models developed are applicable to the replication of convex as well as nonconvex payoffs and to a portfolio of options with different maturities the paper s formulation conveniently accounts for fixed and variable transactions costs lot size constraints and position limits on trading the article shows that in the presence of trading frictions it is no longer optimal to revise one s portfolio in each period at the optimum cash flows in excess of the desired ones may be generated the optimal policy trades off the curvature of the payoff that is generated against the terminal slack

stochastic dominance bounds on derivatives prices in a multiperiod economy with proportional transaction costs by applying stochastic dominance arguments upper bounds on the reservation write price of european calls and puts and lower bounds on the reservation purchase price of these derivatives are derived in the presence of proportional transaction costs incurred in trading the underlying security the primary contribution is the derivation of bounds when intermediate trading in the underlying security is allowed over the life of the option a tight upper bound is derived on the reservation write price of a call and a tight lower bound is derived on the reservation purchase price of a put these results jointly impose tight upper and lower bounds on the implied volatility

reverse speculative attacks abstract in january 2015 in the face of sustained capital inflows the swiss national bank abandoned the floor for the swiss franc against the euro a decision which led to the appreciation of the swiss franc the objective of this paper is to present a simple numerical framework that helps to better understand the timing of this episode which we label a reverse speculative attack we model a central bank which wishes to maintain a peg and responds to increases in demand for domestic currency by expanding its balance sheet in contrast to the classic speculative attacks which are triggered by the depletion of foreign assets reverse attacks are triggered by the concern of future balance sheet losses our key result is that the interaction between the desire to maintain the peg and the concern about future losses can lead the central bank to first accumulate a large amount of reserves and then to abandon the peg just as we have observed in the swiss case

hedging demands in hedging contingent claims minimum variance hedging of a contingent claim in discrete time is suboptimal when the contingent claim is hedged for multiple periods and the objective is to maximize the expected utility of cumulative hedging errors this is because the hedging errors are not independent the difference between a minimum variance hedge and the optimal multiperiod hedge is called the hedging demand and depends on the hedger s preferences the characteristics of the contingent claim the trading frequency and horizon and most importantly the joint distribution of the contingent claim and the underlying security prices since modeling this joint distribution is empirically controversial i examine nonparametrically the economic importance of hedging demands in the case of hedging standard poor s 500 index options

perils of unconventional monetary policy abstract unconventional monetary policy by relaxing restrictions on the composition of the balance sheet of the central bank compromises control over the stochastic path of inflation or in open economies over the stochastic path of exchange rates if the composition of the balance sheet is unrestricted then the path of inflation is indeterminate this is the case under pure quantitative easing where the target is the size of real money balances in contrast credit easing policies restrict the composition of the portfolio by targeting a specific expansion in the maturity profile of bonds bought and thus can implement a determinate path of inflation the composition of the portfolios traded by monetary fiscal authorities also determines premia in asset and currency markets

on the fit of new keynesian models this article provides new tools for the evaluation of dynamic stochastic general equilibrium dsge models and applies them to a large scale new keynesian model we approximate the dsge model by a vector autoregression and then systematically relax the implied cross equation restrictions and document how the model fit changes we also compare the dsge model s impulse responses to structural shocks with those obtained after relaxing its restrictions we find that the degree of misspecification in this large scale dsge model is no longer so large as to prevent its use in day to day policy analysis yet is not small enough to be ignored

hedging derivative securities and incomplete markets an e arbitrage approach given a european derivative security with an arbitrary payoff function and a corresponding set of underlying securities on which the derivative security is based we solve the optimal replication problem find a self financing dynamic portfolio strategy involving only the underlying securities that most closely approximates the payoff function at maturity by applying stochastic dynamic programming to the minimization of a mean squared error loss function under markov state dynamics we derive recursive expressions for the optimal replication strategy that are readily implemented in practice the approximation error or e of the optimal replication strategy is also given recursively and may be used to quantify the degree of market incompleteness to investigate the practical significance of these e arbitrage strategies we consider several numerical examples including path dependent options and options on assets with stochastic volatility and jumps