The savings multiplier

A theory of macroeconomic development based on the novel concept of savings multiplier is developed. Capital accumulation changes relative prices, amplifying incentives to save as the economy grows. The savings multiplier hinges on two mechanisms. First, accumulation raises wages and leads to redistribution from the consuming old to the saving young. Second, higher wages raise the price of old-age care and, in anticipation of this, the young save more. Our theory captures important aspects of China׳s development and suggests new channels through which the one child policy and the dismantling of social benefits have fueled China׳s savings rates.     

Optimal investments for risk- and ambiguity-averse preferences: a duality approach

Ambiguity, also called Knightian or model uncertainty, is a key feature in financial modeling. A recent paper by Maccheroni et al. (preprint, 2004) characterizes investor preferences under aversion against both risk and ambiguity. Their result shows that these preferences can be numerically represented in terms of convex risk measures. In this paper we study the corresponding problem of optimal investment over a given time horizon, using a duality approach and building upon the results by Kramkov and Schachermayer (Ann. Appl. Probab. 9, 904–950, 1999; Ann. Appl. Probab. 13, 1504–1516, 2003). Supported by Deutsche Forschungsgemeinschaft through the SFB 649 “Economic Risk”.     

An examination of the relative economic efficiency of mutual vs. stock savings institutions

This article employs a nonlinear system of Cobb-Douglas profit and input demand equations to analyze price and technical efficiency in a sample of presumably not-for-profit mutual and presumably profit-maximizing stock savings institutions. Theories of property rights and agency are reviewed to provide predictions of price efficiency (i.e., profit maximization and cost minimization behavior), and technical efficiency. The study makes several contributions to the literature. First, it examines the effect of ownership form on both price and technical efficiency. Second, it separately examines the effect of regulatory form on both price and technical efficiency. The model enables us to analyze the separate effects of ownership and regulatory form across a heterogeneous sample of firms. We also analyze the effects of risk in the form of two separate regulatory variables and the effect of market share on economic efficiency.     

Optimal design of equity-linked products with a probabilistic constraint

There is a rich variety of tailored investment products available to the retail investor. These products combine upside participation in bull markets with downside protection in bear markets. Examples include the equity-linked products sold by insurance companies and the structured products marketed by banks. This paper examines a particular contract design for products of this nature. The paper finds the optimal design from the investor's viewpoint. It is assumed that the investor wishes to maximize expected utility of the terminal wealth subject to certain constraints. These constraints include a guaranteed rate of return as well as the opportunity to outperform a benchmark portfolio with a given probability. We derive the explicit form of the optimal design assuming both constraints apply and we illustrate the nature of the solution using some specific examples.     

Optimal commodity taxation with duty-free shopping

International travellers are frequently offered the opportunity to purchase a certain quantity of goods duty-free. Individuals differ in their opportunities to benefit from duty-free shopping, and we focus on the implications of these differences for optimal commodity taxation within a version of the optimal tax model of Mirrlees (Review of Economic Studies, 38, 175–208, 1971). We show how duty-free alters the constraints on the use of commodity taxes to reduce the distortionary costs of income taxation or to reflect externalities. Beyond characterising optimal taxes in the duty-free regime, we discuss conditions under which allowing duty-free would increase or reduce social welfare.      

Optimal portfolio allocation with higher moments

We model the risky asset as driven by a pure jump process, with non-trivial and tractable higher moments. We compute the optimal portfolio strategy of an investor with CRRA utility and study the sensitivity of the investment in the risky asset to the higher moments, as well as the resulting wealth loss from ignoring higher moments. We find that ignoring higher moments can lead to significant overinvestment in risky securities, especially when volatility is high.      

Optimal human capital policies

We analyze optimal income taxes and optimal schooling subsidies in a dynamic private information economy with observable human capital accumulation. We show that under plausible conditions the marginal schooling subsidies are positive and that they are zero at both endpoints of the skill distribution.We compute the optimal policies and evaluate their impact over the transition and at the steady state. We find that the optimal schooling policies are significantly smaller than the optimal marginal income taxes. If optimal schooling policies are introduced jointly with optimal income taxes then their welfare and aggregate effects are small. However, if income taxes are not set optimally then the optimal schooling policies have significant welfare and aggregate effects.     

Financial literacy and voluntary savings for retirement: novel causal evidence

ABSTRACT

We utilise recent Household Finance and Consumption Survey microdata to report first causal effects of financial literacy on voluntary private pension schemes participation for a Central and Eastern European (CEE) country, namely Slovakia. Savings for retirement in the supplementary pension schemes are positively associated with financial literacy after controlling for a set of relevant socio-economic variables. One additional correctly answered financial literacy question leads to a 5.6 percentage points increase in the probability of having a voluntary pension savings plan in our ordinary least squares estimates. The causal impact of financial literacy increases to 19.5 percentage points when we address potential endogeneity problems by novel to the literature instrumental variables.     

Optimal taxation with home production

Optimal taxes for Europe and the U.S. are derived in a realistically calibrated model in which agents buy consumption goods and services and use home capital and labor to produce household services. The optimal tax rate on services is substantially lower than the tax rate on goods. Specifically, the planner cannot tax home production directly and instead lowers the tax rate on market services to increase the relative price of home production. The optimal tax rate on the return to home capital is strictly positive and the welfare gains from switching to optimal taxes are large.     

The term structure of interest rates in a DSGE model with recursive preferences

A dynamic stochastic general equilibrium (DSGE) model in which households have Epstein and Zin recursive preferences is solved with perturbation. The parameters governing preferences and technology are estimated by maximum likelihood using macroeconomic data and the term structure of interest rates. The estimates imply a large risk aversion, an elasticity of intertemporal substitution higher than one, and substantial adjustment costs. Furthermore, the paper identifies the tensions within the model by estimating it on subsets of these data. The analysis concludes by pointing out potential extensions that may improve the model's fit.     

Optimal Mortgage Refinancing with Regime Switches

A model of rational mortgage refinancing is developed where the drift and volatility of interest rate process switch between two regimes. Because of the possibility of a regime shift, the optimal refinancing policy is characterized by the different threshold of interest differential for each regime. Numerical simulation demonstrates that the optimal refinancing threshold in each regime can be smaller or larger than the threshold under single-regime models. Finally, we evaluate the predictions of the model, based on the estimated parameters for a two-regime model to capture the evolution of the mortgage rates in the US. Our model can produce both late and early refinancing, which is consistent with the observed refinancing behavior. The views expressed in this paper are solely those of the authors and do not necessarily reflect official positions of the Sumitomo Trust and Banking Co., Ltd.     

Asset allocation and age effects in retirement savings choices

We examine the asset allocation decisions of members of three large Australian retirement savings funds. Superannuation Guarantee legislation in 1992 made Australian employees compulsory investors by requiring employers to contribute a fixed proportion of earnings to a superannuation fund on behalf of employees. A majority of these employees can choose an investment strategy for these contributions. We examine how actual investment strategy and asset allocation choices of members change with age in view of the conventional wisdom that individuals allocate less to risky assets as they age and investments theory which provides conflicting advice on the issue.     

Optimal taxation and redistribution in an OLG model with unemployment

This paper concerns redistribution via nonlinear income taxation in an overlapping generations model with two ability-types. We assume that the wage rates are determined by bargaining between unions and firms, meaning that the equilibrium is characterized by involuntary unemployment. We show that the policy instruments that are used to calculate the marginal labor income tax rate for each ability-type give rise to intertemporal tax base effects. In addition, since the relationship between the employment and the capital stock implies intertemporal production inefficiency at the second best optimum, imperfect competition in the labor market may itself justify capital income taxation.      

Optimal execution with non-linear transient market impact

We study the problem of the optimal execution of a large trade in the propagator model with non-linear transient impact. From brute force numerical optimization of the cost functional, we find that the optimal solution for a buy programme typically features a few short intense buying periods separated by long periods of weak selling. Indeed, in some cases, we find negative expected cost. We show that this undesirable characteristic of the non-linear transient impact model may be mitigated either by introducing a bid–ask spread cost or by imposing convexity of the instantaneous market impact function for large trading rates; the objective in each case is to robustify the solution in a parsimonious and natural way.     

Optimal monetary policy with endogenous entry and product variety

Deviations from long-run price stability are optimal in the presence of endogenous entry and product variety in a sticky-price model in which price stability would be optimal otherwise Long-run inflation (deflation) is optimal when the benefit of variety to consumers falls short of (exceeds) the market incentive for creating that variety—the desired markup; Price indexation exacerbates this mechanism. Plausible preference specifications and parameter values justify positive long-run inflation rates. However, short-run price stability (around this non-zero trend) is close to optimal, even in the presence of endogenously time-varying desired markups that distort the intertemporal allocation of resources.     

Optimal exercise of executive stock options

Valuing executive stock options is a challenging problem, because the standard risk-neutral valuation of those options is not appropriate; the executive is not allowed to trade the stock of the firm, so is not operating in a complete market. As this paper shows, an executive holding many American-style call options on his firm’s stock will optimally exercise the options bit by bit, whereas a risk-neutral valuation of the options would assume that all are exercised at the same time. Comparative statics of the optimal exercise policy show many surprising features.      

Optimal and equilibrium execution strategies with generalized price impact

This paper examines the execution problems of large traders with a generalized price impact. Constructing two related models in a discrete-time setting, we solve these problems by applying the backward induction method of dynamic programming. In the first problem, we formulate the expected utility maximization problem of a single large trader as a Markov decision process and derive an optimal execution strategy. Then, in the second model, we formulate the expected utility maximization problem of two large traders as a Markov game and derive an equilibrium execution strategy at a Markov perfect equilibrium. Both of these two models enable us to investigate how the execution strategies and trade performances of a large trader are affected by the existence of other traders. Moreover, we find that these optimal and equilibrium execution strategies become deterministic when the total execution volumes of non-large traders are deterministic. We also show, by some numerical examples, the comparative statics results with respect to several problem parameters.     

Optimal income transfers

A substantial literature addresses the design of transfer programs and policies, including the negative income tax, other means-tested transfers, the earned income tax credit, categorical assistance, and work inducements. This work is largely independent of that on the optimal nonlinear income tax, yet formulations of such a tax necessarily address how low-income individuals should be treated. This paper draws on the optimal income taxation literature to illuminate the analysis of transfer programs, including the level and shape of marginal tax rates (including phase-outs), the structure of categorical assistance, and the role of work inducements in an optimal income transfer scheme. JEL Classification H21 · H53 · I38