injecting rational bubbles this paper proves two theorems about economies with a finite number of infinitely lived agents who trade a complete set of one period arrow securities and several infinitely lived securities at each date subject to short sales constraints the first theorem in the paper considers an equilibrium to an economy of this kind it proves that there exists another economy with perturbed short sales constraints in which there is an allocation equivalent equilibrium in which asset prices have a bubble the second theorem extends to the result to the case in short sales constraints are endogenously determined in the sense of alvarez and jermann efficiency equilibrium and asset pricing with risk of default econometrica 68 2000 775 797

macroprudential regulation versus mopping up after the crash this paper compares ex ante policy measures such as macroprudential restrictions on leverage and ex post policy interventions such as bailouts to respond to systemic risk i e to the danger that an economy may experience nancial feedback loops in which falling asset prices declining net worth and tightening nancial constraints reinforce each other ex post policy measures are better targeted since they are taken only once a crisis has materialized but they aggravate the over investment problem ex ante and introduce a time consistency problem ex ante policy measures are more blunt but they can both mitigate the pecuniary externalities that arise during crises and resolve the time consistency problem in ex post policies we nd that except in limit cases it is optimal to respond to systemic risk by using a mix of both ex ante measures and ex post interventions and characterize the optimal policy mix furthermore limiting bailouts to the revenue accumulated in a bailout fund reduces welfare

inefficient credit booms this paper studies the welfare properties of competitive equilibria in an economy with financial frictions hit by aggregate shocks in particular it shows that competitive financial contracts can result in excessive borrowing ex ante and excessive volatility ex post even though from a first best perspective the equilibrium always displays under borrowing from a second best point of view excessive borrowing can arise the inefficiency is due to the combination of limited commitment in financial contracts and the fact that asset prices are determined in a spot market this generates a pecuniary externality that is not internalized in private contracts the model provides a framework to evaluate preventive policies which can be used during a credit boom to reduce the expected costs of a financial crisis copyright 2008 wiley blackwell

management of non maturing deposits by multistage stochastic programming abstract the management of non maturing account positions in a bank s balance like savings and sight deposits as well as certain types of variable rate mortgages is complicated by the embedded options that its clients may exercise in addition to the usual interest rate risk uncertainty in the timing and amount of cash flows must be taken into account when investment or refinancing strategies are determined this paper introduces a multistage stochastic programming model where the stochastic evolution of interest rates and volume under management is described by stochastic processes in discrete time scenarios are generated by means of barycentric approximation which is particularly useful to deal with the observed correlations between interest rates and volume practical experience from the application at a major swiss bank is reported where the model has been employed since the mid 90s

credit and inflation under borrowerʼs lack of commitment here we investigate the existence of credit in a cash in advance economy where there are complete markets but for the fact that agents cannot commit to repay their debts defectors are banned from the credit market but they can use money balances for saving purposes without uncertainty deflation crowds out credit completely the equilibrium allocation however is efficient if the government deflates at the time preference rate efficiency can also be restored with positive inflation for any non negative inflation rate below the optimal level the volume of credit and the real interest rate increase with inflation our results hold when idiosyncratic uncertainty is introduced and households are sufficiently impatient but in one instance efficiency cannot be restored if the deflation rate is nearby the rate of time preference our numerical examples suggest that the optimal inflation rate is not too large for reasonable levels of patience and risk aversion finally we present a framework where the use of money arises endogenously and show that it is tantamount to our cash in advance framework our results hold in this modified environment

lp modeling for asset liability management a survey of choices and simplifications dynamic linear programming lp models for asset liability management alm are quite powerful and flexible but face two challenges 1 many modeling choices not all consistent with one another or with finance theory and 2 solution difficulties due to the large number of scenarios obtained from standard interest rate models we first survey these modeling choices with a view to help researchers make self consistent choices next we review how the dynamic lp model for alm and the representation of uncertainty therein have been simplified in the past to motivate new or hybrid models emphasizing tractability to this end we review existing static lp models as extreme modeling simplifications and aggregation as a simplification of uncertainty

optimal bankruptcy code a fresh start for some abstract what is the optimal consumer bankruptcy law i answer this question using an incomplete markets life cycle model with a planner who can choose state contingent bankruptcy costs i develop two main theoretical characterizations first whenever debt discharge is allowed it should occur without cost second bankruptcy should always be allowed for highly indebted households quantitatively the optimal policy can generate a welfare gain as large as 11 6 however attractive informal default asymmetric information and moral hazard can reduce the welfare gain to as little as 0 7

medium range optimization of copper extraction planning under uncertainty in future copper prices abstract deterministic mine planning models along a time horizon have proved to be very effective in supporting decisions on sequencing the extraction of material in copper mines some of these models have been developed for and used successfully by codelco the chilean state copper company in this paper we wish to consider the uncertainty in a very volatile parameter of the problem namely the copper price along a given time horizon we represent the uncertainty by a multistage scenario tree the resulting stochastic model is then converted into a mixed 0 1 deterministic equivalent model using a compact representation we first introduce the stochastic model that maximizes the expected profit along the time horizon over all scenarios i e as in a risk neutral environment we then present several approaches for risk management in a risk averse environment specifically we consider the maximization of the value at risk and several variants of the conditional value at risk one of them is new the maximization of the expected profit minus the weighted probability of having an undesirable scenario in the solution provided by the model and the maximization of the expected profit subject to stochastic dominance constraints recourse integer for a set of profiles given by the pairs of target profits and bounds on either the probability of failure or the expected profit shortfall we present an extensive computational experience on the actual problem by comparing the risk neutral approach the tested risk averse strategies and the performance of the traditional deterministic approach that uses the expected value of the uncertain parameters the results clearly show the advantage of using the risk neutral strategy over the traditional deterministic approach as well as the advantage of using any risk averse strategy over the risk neutral one

default and aggregate income abstract this paper studies how default varies with aggregate income we analyze a model in which optimal contracts enable risk sharing of privately observed idiosyncratic income by allowing for default default provisions allow agents with low idiosyncratic income realizations to repay less and thus provide insurance default penalties ensure that only these agents default we show that default can occur under the optimal contract and that default provisions vary with aggregate income we provide conditions such that both the amount of default and default penalties vary countercyclically with aggregate income and show that the default rate can be discontinuous

analyzing legal regulations in the norwegian life insurance business using a multistage asset liability management model the legal regulations for the life insurance business in norway have recently been and still are under revision the government s intention is to secure the interests of the customers in life insurance companies however there has been debate as to whether the regulations really are in the customers best interest we apply an asset liability management alm model to analyze the implications of the regulations the model is multistage stochastic and integrates assets and liabilities we employ a four stage model to analyze the legal regulations and conclude that the current legal framework is not in the insurance holders best interests

aggregate consequences of limited contract enforceability we study a general equilibrium model in which entrepreneurs finance investment with optimal financial contracts because of enforceability problems contracts are constrained efficient we show that limited enforceability amplifies the impact of technological innovations on aggregate output this implies that economies with lower enforceability of contracts are characterized by greater macroeconomic volatility a key assumption for the amplification result is that defaulting entrepreneurs are not excluded from the market

collective moral hazard maturity mismatch and systemic bailouts the paper elicits a mechanism by which private leverage choices exhibit strategic complementarities through the reaction of monetary policy when everyone engages in maturity transformation authorities haver little choice but facilitating refinancing in turn refusing to adopt a risky balance sheet lowers the return on equity the key ingredient is that monetary policy is non targeted the ex post benefits from a monetary bailout accrue in proportion to the number amount of leverage while the distortion costs are to a large extent fixed this insight has important consequences first banks choose to correlate their risk exposures second private borrowers may deliberately choose to increase their interest rate sensitivity following bad news about future needs for liquidity third optimal monetary policy is time inconsistent fourth macro prudential supervision is called for we characterize the optimal regulation which takes the form of a minimum liquidity requirement coupled with monitoring of the quality of liquid assets we establish the robustness of our insights when the set of

on the future of macroeconomics a new monetarist perspective this article argues that a pressing goal for macroeconomics is to incorporate financial considerations but we need models with solid microfoundations in particular the use of assets in facilitating exchange as well as different credit or other financial arrangements should be outcomes of not inputs to theories as a preview i suggest that mainstream macro does a good job explaining many phenomena and a financial crisis does not disprove such theory but understanding crises requires better incorporating factors related to money credit banking and liquidity the approach called new monetarist economics can help a lot in this regard

small sample bias and adjustment costs the response of most stock variables e g capital housing consumer durables and prices to exogenous impulses involves a dynamic or short run reaction and a target or long run reaction the difference between these two is typically attributed to some form of adjustment cost in this paper i argue that the small sample problems of cointegrating procedures used to estimate the long run component are particularly severe when adjustment costs are important more precisely elasticity estimates will tend to be biased downward i illustrate the empirical relevance of this by showing that the target elasticity of capital with respect to its cost is severely downward biased when estimated with conventional ols cointegration procedures once this is corrected the elasticity of the u s capital output ratio to the cost of capital is found to be large and close to minus one copyright 1994 by mit press

bubbles and self enforcing debt we characterize equilibria with endogenous debt constraints for a general equilibrium economy with limited commitment in which the only consequence of default is losing the ability to borrow in future periods first we show that equilibrium debt limits must satisfy a simple condition that allows agents to exactly roll over existing debt period by period second we provide an equivalence result whereby the resulting set of equilibrium allocations with self enforcing private debt is equivalent to the allocations that are sustained with unbacked public debt or rational bubbles in contrast to the classic result by bulow and rogoff 1989a positive levels of debt are sustainable in our environment because the interest rate is sufficiently low to provide repayment incentives

financial intermediary capital we propose a dynamic theory of financial intermediaries that are better able to collateralize claims than households that is have a collateralization advantage intermediaries require capital as they have to finance the additional amount that they can lend out of their own net worth the net worth of financial intermediaries and the corporate sector are both state variables affecting the spread between intermediated and direct finance and the dynamics of real economic activity such as investment and financing the accumulation of net worth of intermediaries is slow relative to that of the corporate sector the model is consistent with key stylized facts about macroeconomic downturns associated with a credit crunch namely their severity their protractedness and the fact that the severity of the credit crunch itself affects the severity and persistence of downturns the model captures the tentative and halting nature of recoveries from crises

private capital flows capital controls and default risk abstract what has been the effect of the shift in emerging market capital flows toward private sector borrowers are emerging market capital flows more efficient if not can controls on capital flows improve welfare this paper shows that the answers depend on the form of default risk when private loans are enforceable but there is the risk that the government will default on behalf of all residents private lending is inefficient and capital controls are potentially pareto improving however when private agents may individually default capital flow subsidies are potentially pareto improving

neglected risks financial innovation and financial fragility abstract we present a standard model of financial innovation in which intermediaries engineer securities with cash flows that investors seek but modify two assumptions first investors and possibly intermediaries neglect certain unlikely risks second investors demand securities with safe cash flows financial intermediaries cater to these preferences and beliefs by engineering securities perceived to be safe but exposed to neglected risks because the risks are neglected security issuance is excessive as investors eventually recognize these risks they fly back to the safety of traditional securities and markets become fragile even without leverage precisely because the volume of new claims is excessive

optimal security design how should new securities be designed traditional theories have little to say on this the literature on capital structure and general equilibrium theories with incomplete markets take the securities firms issue as exogenous this paper explicitly incorporates the transaction costs of issuing securities and develops a model where the instruments that are traded are chosen optimally and the economy s market structure is endogenous among other things it is shown that the firm s income stream should be split so that in every state all payoffs are allocated to the security held by the group that values them most this abstract was borrowed from another version of this item

a stochastic programming approach to power portfolio optimization we consider a power portfolio optimization model that is intended as a decision aid for scheduling and hedging dash in the wholesale power market our multiscale model integrates the unit commitment model with financial decision making by including the forwards and spot market activity within the scheduling decision model the methodology is based on a multiscale stochastic programming model that selects portfolio positions that perform well on a variety of scenarios generated through statistical modeling and optimization when compared with several commonly used fixed mix policies our experiments demonstrate that the dash model provides significant advantages

consumer bankruptcy a fresh start consumer bankruptcy provides partial insurance against bad luck but by driving up interest rates makes life cycle smoothing more difficult we argue that to assess this trade off one needs a quantitative model of consumer bankruptcy with three key features life cycle component idiosyncratic earnings uncertainty and expense uncertainty exogenous negative shocks to household balance sheets we find that transitory and persistent earnings shocks have very different implications for evaluating bankruptcy rules more persistent shocks make the bankruptcy option more desirable larger transitory shocks have the opposite effect our findings suggest the current us bankruptcy system may be desirable for reasonable parameter values jel d14 d91 k35

concepts technical issues and uses of the russell yasuda kasai financial planning model this paper discusses technical aspects of the russell yasuda kasai financial planning model these include the models for the discrete distribution scenario generation processes for the uncertain parameters of the model the mathematical approach used to develop the infinite horizon end effects part of the model a comparison of algorithms used in the model s solution and a comparison of the multistage stochastic linear programming model with the previous technology static mean variance analysis experience and benefits of the model in yasuda kasai s financial planning process is also discussed

evolutionary portfolio selection with liquidity shocks insurance companies invest their wealth in financial markets the wealth evolution strongly depends on the success of their investment strategies but also on liquidity shocks which occur during unfavourable years when indemnities to be paid to the clients exceed collected premia an investment strategy that does not take liquidity shocks into account exposes insurance companies to the risk of bankruptcy when liquidity shocks and low investment payoffs jointly appear therefore regulatory authorities impose solvency restrictions to ensure that insurance companies are able to face their obligations with high probability this paper analyses the behaviour of insurance companies in an evolutionary framework we show that an insurance company that merely satisfies regulatory constraints will eventually vanish from the market we give a more restrictive no bankruptcy condition for the investment strategies and we characterize trading strategies that are evolutionary stable i e able to drive out any mutation

a macroeconomic model with a financial sector this paper studies a macroeconomic model in which financial experts borrow from less productive agents we pursue four sets of results i the economy is prone to instability and occasionally enters volatile episodes as volatility spikes agents precautionary motive increases depressing prices even further log linear approximations fail to capture these non linear effects that can cause economies to be significantly depressed for long periods of time ii endogenous risk during volatile episodes increases asset price correlations iii financial experts impose a negative externality on each other and on the labor sector by not maintaining adequate capital cushion and funding structure iv while risk sharing within the financial sector through securitization and derivatives contracts reduces many inefficiencies it can also amlify systemic risks

intertemporal surplus management abstract this paper presents an intertemporal portfolio selection model for pension funds or life insurance funds that maximizes the intertemporal expected utility of the surplus of assets net of liabilities following merton econometrica 41 1973 867 it is assumed that both the asset and the liability return follow ito processes as functions of a state variable the optimum occurs for investors holding four funds the market portfolio the hedge portfolio for the state variable the hedge portfolio for the liabilities and the riskless asset in contrast to merton s result in the assets only case the liability hedge is independent of preferences and only depends on the funding ratio with hara utility the investments in the state variable hedge portfolio are also preference independent finally with log utility the market portfolio investment depends only on the current funding ratio

the impact of energy price shocks on capital formation and economic growth in a putty clay technology since the opec price increases of 1973 and 1979 a number of studies have examined the impact of higher energy prices on labor productivity investment and the capital stock 2 3 7 12 13 14 one of the goals of this research has been to assess the contribution of energy price shocks to the slowdown in long term economic growth that occurred in the 1970s and early 1980s this is an important question because in the long run growth in labor productivity is the principal determinant of increases in the standard of living and over shorter periods of time the level of potential output is a major constraint on the conduct of monetary and fiscal policy energy is an attractive explanation for the slowdown because the timing appears to be correct and the worldwide nature of the problem argues against other theories which are country specific many different types of models have been developed to address these questions but most assume a putty putty production technology in which capital is homogeneous and malleable this causes the economy to adjust rapidly to an increase in energy prices both in the size of the capital stock and in its associated labor and energy requirements however such an assumption is inappropriate in reality the capital stock cannot be instantaneously transformed after an energy price increase and to assume so seriously overstates the speed with which the economy can adapt to the new set of relative prices a more realistic assumption is that the production technology is putty clay factor intensities can be adjusted ex ante according to a smooth neoclassical production function but ex post no substitution is possible firms adjust to a change in relative prices on their new capacity but all old vintages must be replaced before adjustment is complete although the puttyputty and putty clay models eventually achieve the same long run equilibrium their paths to the new steady state are very different the putty putty model jumps immediately to the new

the impact of r d investment on productivity new evidence using linked r d lrd data the impact of r d investment on productivity new evidence using linked r d lrd data this paper uses confidential census longitudinal microdata to examine the association between r d and productivity for the period 1972 1985 these data allow for significant improvements in measurement and model specification yielding more precise estimates of the returns to r d our results confirm the findings of existing studies 1 positive returns to r d investment 2 higher returns to company financed research 3 a productivity premium on basic research these results are robust to adjustments for influential outliers also our evidence suggests that the return to company financed r d is an increasing function of firm size i introduction robert solow s studies in the late 1950s dramatically changed perceptions of the sources of economic growth until this time the commonly held view was that improvements in economic welfare were achieved primarily through the use of more inputs in particular capital input however solow 1957 reported that only 10 percent of the twofold rise in u s per capita output during the years 1909 1949 was due to growth in the capital labor ratio the remainder was attributed to more efficient use of inputs or technological change solow also established a framework for estimating technological change a productivity residual or a measure of changes in output that could not be explained by changes in input use the solow residual in modified form has become virtually synonymous with the measurement of total factor productivity tfp growth jorgenson and griliches 1967 demonstrated that under the assumptions of constant returns to scale and competitive factor pricing changes in total factor productivity measure shifts in a production function rather than treat technological change as exogenous or manna from heaven many economists have explored its determinants r d investment is generally regarded as having a strong impact on productivity growth empirical analysis of the r d productivity connection has often been based on estimation of reduced form equations derived from the r d capital stock model griliches 1979 which extends the solow model to include the stock of technical knowledge or knowledge capital as a factor of production in addition to the standard factors of production physical capital labor intermediate materials and energy if the rate of depreciation of knowledge capital is assumed to be negligible tfp growth dtfp is a function of the intensity of r d investment rdint which is usually measured as the ratio of r d expenditure to sales 1 dtf p sub t alpha beta rdin t sub t u sub t where u sub t is a classical disturbance term the coefficient on r d intensity beta is interpreted as both the marginal product of knowledge capital and the rate of return to r d investment 1 estimates of beta at the company or line of business level are interpreted as measures of the private rate of return to r d or those that accrue to the firm or its investors due to incomplete appropriability or other factors this return may not equal the social return to this activity most empirical studies especially those based on aggregate and sectoral data have found evidence of a strong positive correlation between tfp growth and r d investment however results using firm level data have been mixed the finding that these two variables are uncorrelated is cause for concern because it implies that firms may not be able to earn significant returns on their investment in r d making them less likely to undertake this investment in the future even if it is socially desirable for them to do so we believe that it is important to reestimate this relationship because it is highly likely that existing firm level studies have been based on measures of tfp that are crude imprecise and unrepresentative

dynamic sampling algorithms for multi stage stochastic programs with risk aversion we consider the incorporation of a time consistent coherent risk measure into a multi stage stochastic programming model so that the model can be solved using a sddp type algorithm we describe the implementation of this algorithm and study the solutions it gives for an application of hydro thermal scheduling in the new zealand

lack of recall and centralized monetary trade we introduce lack of recall of past transactions as an alternative assumption to anonymity in a model where trade is centralized in environments where there is an intertemporal lack of double coincidence of wants problem and lack ofcommitment lack of recall can give rise to monetary equilibria that dominate nonmonetary outcomes in terms of welfare

formulation of the russell yasuda kasai financial planning model this paper describes the formulation of the russell yasuda kasai financial planning model including the motivation for the model the presentation complements the discussion of the technical details of the financial modeling process and the managerial impact of its use to help allocate the firm s assets over time discussed in carin o et al 1994 1998 respectively the multistage stochastic linear program incorporates yasuda kasai s asset and liability mix over a five year horizon followed by an infinite horizon steady state end effects period the objective is to maximize expected long run profits less expected penalty costs from constraint violations over the infinite horizon scenarios are used to represent the uncertain parameter distributions the constraints represent the institutional cash flow legal tax and other limitations on the asset and liability mix over time

detrending stylized facts and the business cycle the stylized facts of macroeconomic time series can be presented by fitting structural time series models within this framework we analyse the consequences of the widely used detrending technique popularised by hodrick and prescott 1980 it is shown that mechanical detrending based on the hodrick prescott filter can lead investigators to report spurious cyclical behaviour and this point is illustrated with empirical examples structural time series models also allow investigators to deal explicitly with seasonal and irregular movements that may distort estimated cyclical components finally the structural framework provides a basis for exposing the limitations of arima methodology and models based on a deterministic trend with a single break

the effect of liquidity constraints on consumption a cross sectional analysis this paper examines the effect of liquidity constraints on consumption expenditures using a single year cross section data set a reduced form equation for consumption is estimated on high saving households by the tobit procedure to account for the selectivity bias since high saving households are not likely to be liquidity constrained the estimated equation is an appropriate description of how desired consumption that would be forthcoming without liquidity constraints is related to the variables available in the cross section data when the reduced form equation is used to predict desired consumption the gap between desired consumption and measured consumption is most evident for young households

a multistage linear stochastic programming model for optimal corporate debt management abstract large corporations fund their capital and operational expenses by issuing bonds with a variety of indexations denominations maturities and amortization schedules we propose a multistage linear stochastic programming model that optimizes bond issuance by minimizing the mean funding cost while keeping leverage under control and insolvency risk at an acceptable level the funding requirements are determined by a fixed investment schedule with uncertain cash flows candidate bonds are described in a detailed and realistic manner a specific scenario tree structure guarantees computational tractability even for long horizon problems based on a simplified example we present a sensitivity analysis of the first stage solution and the stochastic efficient frontier of the mean risk trade off a realistic exercise stresses the importance of controlling leverage based on the proposed model a financial planning tool has been implemented and deployed for brazilian oil company petrobras

characterization of a risk sharing contract with one sided commitment in this paper i provide a stopping time based solution to a long term contracting problem between a risk neutral principal and a risk averse agent the agent faces a stochastic income stream and cannot commit to the long term contracting relationship to compute the optimal contract i also design an algorithm that is more efficient than value function iteration

external capital factors and increasing returns in u s manufacturing theoretical models of endogenous growth identify capital accumulation and returns as a potential stimulus to economic growth existing empirical studies however are based on a limited notion of these returns which follows from the simple production function framework used for estimation the purpose of this study is to examine growth issues using dynamic cost function estimation this methodology enables us to broaden the concept of returns to include returns arising from short run quasi fixity of private capital long run internal scale economies and external knowledge factors overall investment in research r d technology high tech capital and education human capital based on detailed industry level data we find evidence of increasing returns to scale arising from cost savings on variable inputs although diminishing returns to capital are prevalent our results also show that knowledge factors augment growth more importantly they appear to explain a substantial proportion of measured

a macroprudential approach to financial regulation many observers have argued that the regulatory framework in place prior to the global financial crisis was deficient because it was largely microprudential in nature a microprudential approach is one in which regulation is partial equilibrium in its conception and aimed at preventing the costly failure of individual financial institutions by contrast a macroprudential approach recognizes the importance of general equilibrium effects and seeks to safeguard the financial system as a whole in the aftermath of the crisis there seems to be agreement among both academics and policymakers that financial regulation needs to move in a macroprudential direction in this paper we offer a detailed vision for how a macroprudential regime might be designed our prescriptions follow from a specific theory of how modern financial crises unfold and why both an unregulated financial system as well as one based on capital rules that only apply to traditional banks is likely to be fragile we begin by identifying the key market failures at work why individual financial firms acting in their own interests deviate from what a social planner would have them do next we discuss a number of concrete steps to remedy these market failures we conclude the paper by comparing our proposals to recent regulatory reforms in the united states and to proposed global banking reforms

optimal deleveraging with nonlinear temporary price impact abstract in this paper we first propose a portfolio management model where the objective is to balance equity and liability the asset price dynamics includes both permanent and temporary price impact where the permanent impact is a linear function of the cumulative trading amount and the temporary impact is a k th between 0 and 1 order power function of the instantaneous trading rate we construct efficient frontiers to visualize the tradeoff between equity and liability and obtain analytical properties regarding the optimal trading strategies in the second part we further consider an optimal deleveraging problem with leverage constraints it reduces to a non convex polynomial optimization program with polynomial and box constraints a lagrangian method for solving the problem is presented and the quality of the solution is studied

international coordination of fiscal policy in limiting economies we examine the limiting behavior of cooperative and noncooperative fiscal policies as countries market power goes to zero we show that these policies converge if countries raise revenues through lump sum taxation however if there are unremovable domestic distortions such as distorting taxes there can be gains to coordination even when a single country s policy cannot affect world prices these results differ from the received wisdom in the optimal tariff literature the key distinction is that contrary to the tariff literature the spending decisions of governments are explicitly modeled

a bank asset and liability management model in managing its assets and liabilities in light of uncertainties in cash flows cost of funds and return on investments a bank must determine its optimal trade off between risk return and liquidity in this paper we develop a multiperiod stochastic linear programming model alm that includes the essential institutional legal financial and bank related policy considerations and their uncertainties yet is computationally tractable for realistically sized problems a version of the model was developed for the vancouver city savings credit union for a 5 year planning period the results indicate that alm is theoretically and operationally superior to a corresponding deterministic linear programming model and that the effort required for the implementation of alm and its computational requirements are comparable to those of the deterministic model moreover the qualitative and quantitative characteristics of the solutions are sensitive to the model s stochastic elements such as the asymmetry of cash flow distributions we also compare alm with the stochastic decision tree sdt model developed by s p bradley and d b crane alm is computationally more tractable on realistically sized problems than sdt and simulation results indicate that alm generates superior policies

generation capacity expansion in a risky environment a stochastic equilibrium analysis we cast models of the generation capacity expansion type formally developed for the monopoly regime into equilibrium models better adapted for a competitive environment we focus on some of the risks faced today by investors in generation capacity and thus pose the problem as a stochastic equilibrium model we illustrate the approach on the problem of the incentive to invest agents can be risk neutral or risk averse we model risk aversion through the cvar of plants profit the cvar induces risk adjusted probabilities according to which investors value their plants the model is formulated as a complementarity problem including the cvar valuation of investments an illustration is provided on a small problem that captures several features of today s electricity world a choice often restricted to coal and gas units a peaky load curve because of wind penetration uncertain fuel prices and an evolving carbon market we assess the potential of the approach by comparing energy only and capacity market organizations in this risky environment our results can be summarized as follows a deterministic analysis overlooks some changes of capacity structure induced by risk whether in the capacity market or energy only organizations the risk neutral analysis also misses a shift towards less capital intensive technologies that may result from risk aversion last risk aversion also increases the shortage of capacity compared to the risk neutral view in the energy only market when the price cap is low this may have a dramatic impact on the bill to the final consumer the approach relies on mathematical programming techniques and can be extended to full size problems the results are illustrative and may deserve more investigation

searching for a break in gnp it has been suggested that existing estimates of the long run impact of a surprise move in income may have a substantial upward bias due to the presence of a trend break in postwar u s gross national product data this article shows that the statistical evidence does not warrant abandoning the no trend break null hypothesis a key part of the argument is that conventionally computed p values overstate the likelihood of the trend break alternative hypothesis this is because they do not take into account that in practice the date is chosen based on pretest examination of the data

endogenous technical advance and the stochastic trend in output a neoclassical approach abstract in the recent endogenous growth literature the trend in output is stochastic while investment in scientific knowledge is treated as analogous to a capital stock this paper models both research and development r d and disembodied technical advance using neo classical equations which specify the equilibrium stocks as a function of prices and output the elasticity of r d in the production function estimated using factor shares is time varying and increasing returns to scale are increasing in all factors the most important aspect of the model is that the equilibrium rate of technical advance is not cyclically invariant but co moves with output at business cycle frequencies this allows the production function to behave as a stochastic trend growth accounting demonstrates that long term variations in the rate of productivity growth have been associated mainly with low frequency fluctuations in the rate of disembodied technical advance with secondary effects from the stocks of r d and physical capital during the high productivity period 1948 1972 technical advance contributed 1 48 percentage points per year to output with 0 98 accounted for by r d the productivity slowdown of the mid 1970s was accounted by a gradual decline in the effect of r d and a more abrupt collapse in disembodied technology the subsequent productivity revival was associated with two accelerations in disembodied technical advance the first beginning in the early 1980s and the second in the mid 1990s the production function is simulated in a small econometric model model simulations find that exogenous shocks to the inflation rate generate significant variations in growth by inducing fluctuations in disembodied technology

stochastic network programming for financial planning problems several financial planning problems are posed as dynamic generalized network models with stochastic parameters examples include asset allocation for portfolio selection international cash management and programmed trading arbitrage despite the large size of the resulting stochastic programs the network structure can be exploited within the solution strategy giving rise to efficient implementations empirical results are presented indicating the benefits of the stochastic network approach for the asset allocation case

a model of capital and crises we develop a model in which the capital of the intermediary sector plays a critical role in determining asset prices the model is cast within a dynamic general equilibrium economy and the role for intermediation is derived endogenously based on optimal contracting considerations low intermediary capital reduces the risk bearing capacity of the marginal investor we show how this force helps to explain patterns during financial crises the model replicates the observed rise during crises in sharpe ratios conditional volatility correlation in price movements of assets held by the intermediary sector and fall in riskless interest rates

on line portfolio selection using stochastic programming abstract this paper is dedicated to the problem of dynamic portfolio optimization for the case when the number of decision periods is large and new information about market arrives during each such period we propose the family of adaptive portfolio selection policies which rebalance the current portfolio during each decision period by adopting portfolio from a specified family with the best performance on the past data in the absence of transaction costs the general conditions are found under which this policy yields asymptotically the same performance as the best portfolio from the same family constructed with the full knowledge of the future these results are extended for the case of nonzero transaction costs by introducing a class of threshold portfolio optimization policies which rebalance current portfolio only when its performance differs from performance of the best portfolio by a given threshold the value of this threshold is adapted to the changing market conditions we show that it is possible to select a sequence of threshold values in such a way that the asymptotic influence of transaction costs on portfolio performance is negligible and overall portfolio performance is asymptotically the same as the performance of portfolio with the perfect knowledge of the future we do not assume neither specific probabilistic structure of the market data nor their stationarity our theory is illustrated by numerical experiments with real data finally we discuss the relevance of our results in the context of high performance computing

jointly optimal regulation of bank capital and liquidity in an economy with financial frictions banks endogenously choose excessive leverage and maturity mismatch in equilibrium as they fail to internalize the risk of socially wasteful fire sales macroprudential regulators can achieve efficiency with simple linear constraints which require less information than pigouvian taxes the liquidity coverage and net stable funding ratios of basel iii can implement efficiency additional microprudential regulation of leverage is required when bank failures are socially costly micro and macroprudential rules are imperfect substitutes optimally macroprudential policy reacts to systematic risk and credit conditions over the cycle while microprudential policy reacts to systematic and idiosyncratic risk

computers obsolescence and productivity this paper develops a new technique for measuring the effect of computer usage on u s productivity growth standard national income and product accounts nipa measures of the computer capital stock which are constructed by weighting past investments according to a schedule for economic depreciation the rate at which capital loses value as it ages are shown to be inappropriate for growth accounting because they do not capture the effect of a unit of computer capital on productivity this is due to technological obsolescence machines that are still productive are retired because they are no longer near the technological frontier and anticipation of retirement affects economic depreciation using a model that incorporates obsolescence alternative stocks are developed that imply a larger computer usage effect this effect together with the direct effect of increased productivity in the computer producing sector accounted for the improvement in u s productivity growth over 1996 1998 relative to the

schumann a modeling framework for supply chain management under uncertainty abstract we present a modeling framework for the optimization of a manufacturing assembly and distribution mad supply chain planning problem under uncertainty in product demand and component supplying cost and delivery time mainly the automotive sector has been chosen as the pilot area for this type of multiperiod multiproduct multilevel problem but the approach has a far more reaching application a deterministic treatment of the problem provides unsatisfactory results we use a 2 stage scenario analysis based on a partial recourse approach where mad supply chain policy can be implemented for a given set of initial time periods such that the solution for the other periods does not need to be anticipated and then it depends on the scenario to occur in any case it takes into consideration all the given scenarios very useful schemes are used for modeling balance equations and multiperiod linking constraints a dual approach splitting variable scheme is been used for dealing with the implementable time periods related variables via a redundant circular linking representation

externalities in economies with imperfect information and incomplete markets this paper presents a simple general framework for analyzing externalities in economies with incomplete markets and imperfect infonnation by identifying the pecuniary effects of these externalities that net out the paper simplifies the problem of determining when tax interventions are pareto improving the approach indicates that such tax interventions almost always exist and that equilibria in situations of imperfect information are rarely constrained pareto optima it can also lead to simple tests based on readily observable indicators of the efficacy of particular tax policies in situations involving adverse selection signaling moral hazard incomplete contingent claims markets and queue rationing equilibria traditional discussions of externalities have emphasized the distinction between technological externalities in which the action of one individual or firm directly affects the utility or profit ofanother and pecuniary externalities in which one individual s or firm s actions affect another only through effects on prices while the presence of technological externalities imply in general that a competitive equilibrium may not be pareto efficient pecuniary externalities hy themselves are not a source of inefficiency the fact that prices change has of course important consequences there are both distributional and allocational effects but the distribution effects net out gains for example hy firms whose prices increase are precisely offset by losses e g to individuals who must pay higher prices and there are no welfare losses from the allocation effects as long as the price changes involved are small if firms are maximizing profits and individuals are maximizing utility both facing prices that correctly refiect opportunity costs then standard envelope theorem arguments imply that changes in profits or utility induced by changes in allocations resulting from any small change in prices are negligible

multi period stochastic optimization models for dynamic asset allocation abstract institutional investors manage their strategic asset mix over time to achieve favorable returns subject to various uncertainties policy and legal constraints and other requirements one may use a multi period portfolio optimization model in order to determine an optimal asset mix the concept of scenarios is typically employed for modeling random parameters in a multi period stochastic programming model and scenarios are constructed via a tree structure recently an alternative stochastic programming model with simulated paths was proposed by hibiki hibiki n 2001b a hybrid simulation tree multi period stochastic programming model for optimal asset allocation in takahashi h ed the japanese association of financial econometrics and engineering jafee journal 89 119 in japanese hibiki n 2003 a hybrid simulation tree stochastic optimization model for dynamic asset allocation in scherer b ed asset and liability management tools a handbook for best practice risk books pp 269 294 and it is called a hybrid model the advantage of the simulated path structure compared to the tree structure is to give a better accuracy to describe uncertainties of asset returns in this paper we compare the two types of multi period stochastic optimization models and clarify that the hybrid model can evaluate and control risk better than the scenario tree model using some numerical tests according to the numerical results an efficient frontier of the hybrid model with the fixed proportion strategy dominates that of the scenario tree model when we evaluate them on simulated paths moreover optimal solutions of the hybrid model are more appropriate than those of the scenario tree model

the role of intergenerational transfers in aggregate capital accumulation this paper uses historical u s data to directly estimate the contribution of intergenerational transfers to aggregate capital accumulation the evidence presented indicates that intergenerational transfers account for the vast majority of aggregate u s capital formation only a negligible fraction of actual capital accumulation can be traced to life cycle or hump savings a major difference between this study and previous investigations of this issue is the use of more accurate longitudinal age earnings and age consumption profiles these profiles are simply too flat to generate substantial life cycle savings this paper suggests the importance of and need for substantially greater research and data collection on intergenerational transfers life cycle models of savings that emphasize savings for retirement as the dominant form of capital accumulation should give way to models that illuminate the determinants of intergenerational transfers

risk sharing within families evidence from the health and retirement study abstract we report strong empirical support for the presence of self interest based risk sharing within extended families in the u s a standard model of self interest based risk sharing predicts that the share of current family income consumed by a child positively depends on that child s permanent income it follows that parental transfers to children that are expected to earn more over the period of risk sharing arrangements should exhibit less sensitivity to the recipient s income fluctuations we test this distinguishing prediction of self interest based risk sharing by exploiting the variation of transfer receipts among siblings observed over 17 years of longitudinal data spanned by the health and retirement study

monetary policy as financial stability regulation this paper develops a model that speaks to the goals and methods of financialstability policies there are three main points first from a normative perspective the model defines the fundamental market failure to be addressed namely that unregulated private money creation can lead to an externality in which intermediaries issue too much short term debt and leave the system excessively vulnerable to costly financial crises second it shows how in a simple economy where commercial banks are the only lenders conventional monetary policy tools such as open market operations can be used to regulate this externality while in more advanced economies it may be helpful to supplement monetary policy with other measures third from a positive perspective the model provides an account of how monetary policy can influence bank lending and real activity even in a world where prices adjust frictionlessly and there are other transactions media besides bank created money that are outside the control of the central bank

short term financial planning under uncertainty this paper presents a stochastic linear programming formulation of a firm s short term financial planning problem this framework allows a more realistic representation of the uncertainties fundamental to this problem than previous models in addition using wets s algorithm for linear simple recourse problems this formulation has approximately the same computational complexity as the mean approximation i e the deterministic program obtained by replacing all random elements by their means using this formulation we empirically investigate the effects of differing distributions and penalty costs we conclude that even with symmetric penalty costs and distributions the mean model is significantly inferior to the stochastic linear programming formulation thus we are able to demonstrate that ignoring the stochastic components in linear programming formulations can be very costly without having significant computational savings

pareto optima and competitive equilibria with adverse selection and moral hazard this paper explores the extent to which standard general equilibrium analysis of pareto optima and of competitive equilibria can be applied to environments with moral hazard and adverse selection problems allowing for lotteries contracts with random components we first establish that an adverse selection insurance economy a moral hazard insurance economy a signaling economy and a private information labor market economy are all special cases of a simple general structure we then show that techniques for characterizing pareto optimal contracts as solutions to concave programming problems are useful and nice and appear to be broadly applicable allowing for lotteries we show how to characterize the optimal allocations for the adverse selection insurance and labor market economies we then show that standard existence and optimality theorems for competitive equilibria apply in the linear space containing lotteries if agents with characteristics which are distinct and privately observed at the time of initial trading enter the economy wide resource constraints in a homogeneous way other kinds of diversity are not critical for economies with moral hazard which satisfy the homogeneity condition competitive contract markets single out a subset of the optima and thus can be consistent with apparent unemployment and with a random allocation of labor supplied though all households are averse to risk the adverse selection insurance and signaling economies however do not satisfy the homogeneity condition and are difficult to decentralize efficiently with a price system

intermediary asset pricing abstract we model the dynamics of risk premia during crises in asset markets where the marginal investor is a financial intermediary intermediaries face an equity capital constraint risk premia r

modeling financial reinsurance in the casualty insurance business via stochastic programming abstract in this paper we examine the rationale for financial reinsurance in the casualty insurance business as opposed to regular reinsurance financial reinsurance refers to an investment strategy that uses the financial markets to hedge insurance risk the casualty insurer takes positions in derivatives on underlying assets whose prices are highly positively or negatively correlated with specific insurance risks we formulate the asset liability management problem for a mutually owned casualty insurer in the context of a dynamic stochastic portfolio selection model using numerical studies of the resulting large scale non linear program we compare properties of optimal portfolios with and without the possibility of financial reinsurance we let an alleged representative policyholder endowed with a linear plus negative exponential utility function evaluate the various optimal portfolios when policyholders utility functions exhibit reasonable levels of risk aversion we find that portfolios reflecting financial reinsurance dominate portfolios that are not financially reinsured

optimal savings management for individuals with defined contribution pension plans abstract the paper provides some guidelines to individuals with defined contribution dc pension plans on how to manage pension savings both before and after retirement we argue that decisions regarding investment annuity payments and the size of death sum should not only depend on the individual s age or time left to retirement nor should they solely depend on the risk preferences but should also capture 1 economical characteristics such as current value on the pension savings account expected pension contributions mandatory and voluntary and expected income after retirement e g retirement state pension and 2 personal characteristics such as risk aversion lifetime expectancy preferable payout profile bequest motive and preferences on portfolio composition specifically the decisions are optimal under the expected crra utility function and are subject to the constraints characterizing the individual the problem is solved via a model that combines two optimization approaches stochastic optimal control and multi stage stochastic programming the first method is common in financial and actuarial literature but produces theoretical results however the latter which is characteristic for operations research has practical applications we present the operations research methods which have potential to stimulate new thinking and add to actuarial practice

capital growth with security abstract this paper discusses the allocation of capital over time with several risky assets the capital growth log utility approach is used with conditions requiring that specific goals are achieved with high probability the stochastic optimization model uses a disjunctive form for the probabilistic constraints which identifies an outer problem of choosing an optimal set of scenarios and an inner conditional problem of finding the optimal investment decisions for a given scenarios set the multiperiod inner problem is composed of a sequence of conditional one period problems the theory is illustrated for the dynamic allocation of wealth in stocks bonds and cash equivalents

hierarchical model for production planning in the case of uncertain demand the paper deals with hierarchical production planning for a multiperiod model consisting of an aggregate planning level and a detailed planning level in the case of uncertain demand at the beginning the detailed demand for the actual planning period is known whereas for future planning periods only upper and lower bounds of detailed demand are known on the other hand the aggregate demand on the product group level is supposed to be deterministic at each planning period over the whole planning horizon for the aggregate planning level robust production plans i e aggregate production plans which can be disaggregated to a feasible detailed plan for every possible detailed demand are proposed and a consistent disaggregation is executed for the detailed planning level two sets static and dynamic of sufficient conditions for robustness of the aggregate plan as well as dynamic disaggregation conditions are derived these sufficient conditions are a generalization of the results of lasserre and merce the performance of the sufficient conditions are demonstrated by a computational study which shows the potential advantage of the approach

on efficient distribution with private information this paper is a study of the dynamics of the efficient distribution of consumption in an exchange economy with many consumers each of whom is subject to private idiosyncratic taste shocks we propose a recursive method for finding feasible allocations that are incentivecompatible and that are pareto optimal within this set the method is applied to several parametric examples we find that in an efficient allocation the degree of inequality continually increases with a diminishing fraction of the population receiving an increasing fraction of the resources we discuss the extent to which these allocations can be decentralized via market arrangements this paper is a study of the dynamics of the efficient distribution of consumption in an exchange economy with private information the economy we study has a constant endowment flow of a single non storable consumption good which is to be allocated each period among a large number of consumers each period these consumers experience unpredictable idiosyncratic privately observed taste shocks affecting their marginal utility of current consumption efficiency dictates that more resources be allocated to those consumers who in any given period have a high marginal utility of current consumption

educational policy in a credit constrained economy with skill heterogeneity an overlapping generations model where agents choose whether to become educated when young is presented education enhances productivity but needs to be financed by borrowing because of the possibility of default lenders may ration credit we characterize the steady state equilibrium with and without credit constraints and show that credit constraints are associated with lower education and a lower real interest rate we then study the role of public policy in remedying the inefficiency which occurs with credit market imperfections and examine whether public education can improve on the constrained equilibrium

cost risk balanced management of scarce resources using stochastic programming we consider the situation when a scarce renewable resource should be periodically distributed between different users by a resource management authority rma the replenishment of this resource as well as users demand is subject to considerable uncertainty we develop cost optimization and risk management models that can assist the rma in its decision about striking the balance between the level of target delivery to the users and the level of risk that this delivery will not be met these models are based on utilization and further development of the general methodology of stochastic programming for scenario optimization taking into account appropriate risk management approaches by a scenario optimization model we obtain a target barycentric value with respect to selected decision variables a successive reoptimization of deterministic model for the worst case scenarios allows the reduction of the risk of negative consequences derived from unmet resources demand our reference case study is the distribution of scarce water resources we show results of some numerical experiments in real physical systems

on endogenous formation of price expectations abstract we study a two period exchange economy with complete financial markets and endogenous borrowing constraints contrary to perfect foresight paradigm we assume that agents are heterogeneous in their ability to forecast future prices we introduce a new equilibrium concept called informationally constrained equilibrium where the formation of price expectations is endogenous and reflects the revelation of information from observing bounds on liabilities designed to ensure solvency at any contingency we prove that under standard assumptions an equilibrium always exists and we characterize the degree of information revealed by the endogenous debt limits

optimal lending contracts and firm dynamics we develop a general model of lending in the presence of endogenous borrowing constraints borrowing constraints arise because borrowers face limited liability and debt repayment cannot be perfectly enforced in the model the dynamics of debt are closely linked with the dynamics of borrowing constraints in fact borrowing constraints must satisfy a dynamic consistency requirement the value of outstanding debt restricts current access to short term capital but is itself determined by future access to credit this dynamic consistency is not guaranteed in models of exogenous borrowing constraints where the ability to raise short term capital is limited by some prespecified function of debt we characterize the optimal default free contract which minimizes borrowing constraints at all histories and derive implications for firm growth survival leverage and debt maturity the model is qualitatively consistent with stylized facts on the growth and survival of firms comparative statics with respect to technology and default constraints are derived borrowing constraints are an important determinant of firm growth and survival 1 such constraints may arise in connection to the financing of investment opportunities faced by firms or temporary liquidity needs such as those required to survive a recession this paper develops a theory of endogenous borrowing constraints and studies its implications for firm dynamics in our model debt is constrained by the firm s limited liability and option to default a lending contract specifies an initial loan size future financing and a repayment schedule the choice of these variables in turn determines future growth the firm s future borrowing capacity and its ability and willingness to repay hence borrowing constraints and firm dynamics are jointly determined we study this dynamic design problem our model builds on thomas and worral s 1994 model of foreign direct investment at time zero a risk neutral borrower firm or entrepreneur has a project which requires a fixed initial set up cost every period the project yields revenues that increase with the amount of 1 there is considerable evidence suggesting that financing constraints are important determinants of firm dynamics gertler and gilchrist 1994 argue that liquidity constraints may explain why small manufacturing firms respond more to a tightening of monetary policy than do larger manufacturing firms perez quiros and timmermann 2000 show that in recessions smaller firms are more sensitive to the worsening of credit market conditions as measured by higher interest rates and default premia evans and jovanovic 1989 show that the liquidity constraints are essential in the decision to become an entrepreneur fazzari hubbard and petersen 1988 among others view financial constraints as an explanation for the dynamic behaviour of aggregate investment and cabral and mata 1996 are able to fit reasonably well the size distribution of portuguese manufacturing firms by estimating a simple model of financing constraints for surveys see hubbard 1998 and stein 2003

back testing the performance of an actively managed option portfolio at the swedish stock market 1990 1999 we build an investment model based on stochastic programming in the model we buy at the ask price and sell at the bid price we apply the model to a case where we can invest in a swedish stock index call options on the index and the risk free asset by reoptimizing the portfolio on a daily basis over a ten year period it is shown that options can be used to create a portfolio that outperforms the index with ex post analysis it is furthermore shown that we can create a portfolio that dominates the index in terms of mean and variance i e at given level of risk we could have achieved a higher return using options

intertemporal distortions in the second best we consider a very general class of public nance problems that encompasses ramsey models of optimal taxation as well as economies with limited commitment private information and political economy frictions we identify a su cient condition to rule out permanent intertemporal distortions at the optimum if there exists an admissible allocation that converges to the rst best steady state then all intertemporal distortions are temporary in the second best we analyze a series of applications to illustrate the signi cance of this result

competitive risk sharing contracts with one sided commitment this paper analyzes dynamic equilibrium risk sharing contracts between profit maximizing intermediaries and a large pool of ex ante identical agents that face idiosyncratic income uncertainty that makes them heterogeneous ex post in any given period after having observed her income the agent can walk away from the contract while the intermediary cannot i e there is one sided commitment we consider the extreme scenario that the agents face no costs to walking away and can sign up with any competing intermediary without any reputational losses we demonstrate that not only autarky but also partial and full insurance can obtain depending on the relative patience of agents and financial intermediaries insurance can be provided because in an equilibrium contract an up front payment effectively locks in the agent with an intermediary we then show that our contract economy is equivalent to a consumption savings economy with one period arrow securities and a short sale constraint similar to bulow and rogoff 1989 from this equivalence and our characterization of dynamic contracts it immediately follows that without cost of switching financial intermediaries debt contracts are not sustainable even though a risk allocation superior to autarky can be achieved

applying cvar for decentralized risk management of financial companies abstract over the past decade financial companies have merged diverse areas including investment banking insurance retail banking and trading operations despite this diversity many global financial firms suffered severe losses during the recent recession to reduce enterprise risks and increase profits we apply a decentralized risk management strategy based on a stochastic optimization model we extend the decentralized approach with the cvar risk metric showing the advantages of cvar over traditional risk measures such as value at risk an example taken from the earthquake insurance area illustrates the concepts

excessive dollar debt financial development and underinsurance we propose that the limited financial development of emerging markets is a significant factor behind the large share of dollar denominated external debt present in these markets we show that when financial constraints affect borrowing and lending between domestic agents agents undervalue insuring against an exchange rate depreciation since more of this insurance is present when external debt is denominated in domestic currency rather than in dollars this result implies that domestic agents choose excessive dollar debt we also show that limited financial development reduces the incentives for foreign lenders to enter emerging markets the retarded entry reinforces the underinsurance problem

optimal taxation in a limited commitment economy this paper studies optimal ramsey taxation when risk sharing in private insurance markets is imperfect due to limited enforcement in a limited commitment economy there are externalities associated with capital and labor because individuals do not take into account that their labor and saving decisions aect aggregate supply wages

collateral motivated financial innovation collateral frictions have a profound effect on our economic landscape ranging from the design of financial securities laws and institutions to various rules and regulations we analyze a model with disagreement where securities and collateral requirements are endogenous it shows that the security that isolates the variable with disagreement is optimal in the sense that alternative securities cannot generate any trading in an economy with n states investors may introduce more than n securities and markets are still incomplete the model has several novel predictions on the behavior of basis the spread between the prices of an asset and its replicating portfolio

debt constrained asset markets we develop a theory of general equilibrium with endogenous debt limits in the form of individual rationality constraints similar to those in the dynamic consistency literature if an agent defaults on a contract he can be excluded from future contingent claims markets trading and can have his assets seized he cannot be excluded from spot markets trading however and he has some private endowments that cannot be seized all information is publicly held and common knowledge and there is a complete set of contingent claims markets since there is complete information an agent cannot enter into a contract in which he would have an incentive to default in some state in general there is only partial insurance variations in consumption may be imperfectly correlated across agents interest rates may be lower than they would be without constraints and equilibria may be pareto ranked

do we need a price index for industrial r d abstract price deflators for research expenditures of 12 individual industries and of all u s industries combined are constructed for the period 1969 1988 these indexes are derived with a set of proxy price series that are highly correlated with surveyed r d input prices and that may be easily extended forward in time as the requisite proxy data become available the approach could be replicated for other countries given the recent consideration to treat r d as part of capital formation in satellite accounts to the international system of national accounts and the u s national income and product accounts there is an immediate need for such deflators trends in u s industrial r d expenditures utilizing these r d deflators and others found in the literature are contrasted although broad based deflators such as the gnp deflator used in reporting most official r d statistics provide reasonable approximations of changes in aggregate industry r d costs they are much less appropriate for calculating real r d expenditures of individual industries the industry specific r d indexes built here rather readily capture variations in inter industry r d cost trends that broader deflators miss