Mean-reversion properties of implied volatilities

In this paper, we present a new stylized fact for options whose underlying asset is a stock index. Extracting implied volatility time series from call and put options on the Deutscher Aktien index (DAX) and financial times stock exchange index (FTSE), we show that the persistence of these volatilities depends on the moneyness of the options used for its computation. Using a functional autoregressive model, we show that this effect is statistically significant. Surprisingly, we show that the diffusion-based stochastic volatility models are not consistent with this stylized fact. Finally, we argue that adding jumps to a diffusion-based volatility model help recovering this volatility pattern. This suggests that the persistence of implied volatilities can be related to the tails of the underlying volatility process: this corroborates the intuition that the liquidity of the options across moneynesses introduces an additional risk factor to the one usually considered.     

On the coexistence of money and higher-return assets and its social role

This paper adopts mechanism design to investigate the coexistence of fiat money and higher-return assets. We consider an economy with pairwise meetings where fiat money and risk-free capital compete as means of payment, as in [28]. The trading mechanism in pairwise meetings is chosen among all individually rational, renegotiation-proof mechanisms to maximize society?s welfare. We show that in any stationary monetary equilibrium capital commands a higher rate of return than fiat money.     

Profitability and opportunity of conservation agriculture in acid savannah grasslands of Laos

In north-eastern Laos, the savannah grasslands of the Plain of Jars cover vast areas of potentially cultivable land. However, soil acidity, low inherent fertility, and the absence of alternatives to tillage represent significant constraints to the development of sustainable smallholder agriculture. Our objective was to evaluate the potential for conservation agriculture (CA) to enhance soil productivity and farming system profitability. A three-year rotation of rice/maize/soybean was tested under three fertilization levels and four agricultural systems: one conventional tillage-based (CT) system and three CA systems based on no-tillage with cover crops. After four cropping seasons, our results show that, compared with CT, CA systems led to similar-to-higher grain production, similar-to-higher profits, higher opportunity of livestock system intensification, and higher labour productivity regardless of fertilization levels. While CA represents a relevant alternative to current practices, our results suggest that its contribution to the emergence of a sustainable smallholder agriculture is conditioned by broader institutional transformations, including the enrolment of local manufacturers and traders for deploying no-till implements and seed market channels for cover crops, long-term public support to maintain active research and technical mentoring to farmers, and possibly the integration of ecosystem services in agricultural policy.     

State-dependent pricing, inflation, and welfare in search economies

We investigate the welfare effects of inflation in economies with search frictions and menu costs. We first analyze an economy where there is no transaction demand for money balances: Money is a mere unit of account. We determine a condition under which strictly positive inflation is desirable. We relate this condition to a standard efficiency condition for search economies. Second, we consider a related economy in which there is a transaction role for money. In the absence of menu costs, the Friedman rule is optimal. In the presence of menu costs, the optimal inflation rate is negative for our numerical examples provided menu costs are small. A deviation from the Friedman rule can be optimal depending on the extent of the search externalities.     

The American frontier: Technology versus immigration

How important was international immigration for the US and its demography during the nineteenth century? This paper investigates, quantitatively, its effect on the westward movement of population and the regional and secular changes in fertility. Beside immigration, two alternative forces are considered: technological progress and the land policy (the Homestead Act). An optimal growth model with endogenous fertility and migration is calibrated, and counterfactual experiments reveal that the main driving forces were productivity growth and the declining cost of transportation. International immigration played a lesser role.     

A quantitative analysis of China's structural transformation

The structural transformation of China - or the reallocation of resources from the agricultural sector to the nonagricultural sector - between 1978 and 2003 was truly remarkable. We develop a two-sector neoclassical growth model to quantitatively assess the driving forces of China's recent structural transformation. In addition to the forces currently emphasized in the literature-sectoral productivity growth—we show that China's transformation was accelerated significantly by the gradual reduction in the relative size of the Chinese government. We find that the reduction in the size of the Chinese government accounted - by itself - for 15% of the reduction in the agricultural share of employment. Two mechanisms explain this: (i) in our model the lower tax rate associated with reduced intervention encouraged the accumulation of physical capital, which is produced in the nonagricultural sector; (ii) lower inefficiencies induced incomes to rise and, given our preferences, resulted in a disproportionate increase in the demand for the nonagricultural good.     

LIQUIDATION OF AN INDIVISIBLE ASSET WITH INDEPENDENT INVESTMENT

We provide an extension of the explicit solution of a mixed optimal stopping–optimal stochastic control problem introduced by Henderson and Hobson. The problem examines whether the optimal investment problem on a local martingale financial market is affected by the optimal liquidation of an independent indivisible asset. The indivisible asset process is defined by a homogeneous scalar stochastic differential equation, and the investor's preferences are defined by a general expected utility function. The value function is obtained in explicit form, and we prove the existence of an optimal stopping–investment strategy characterized as the limit of an explicit maximizing strategy. Our approach is based on the standard dynamic programming approach.     

Inflation and Unemployment in General Equilibrium*

When labor is indivisible, there exist efficient outcomes with some agents randomly unemployed, as in Rogerson (1988) . We integrate this idea into the modern theory of monetary exchange, where some trade occurs in centralized markets and some in decentralized markets, as in Lagos and Wright (2005) . This delivers a general equilibrium model of unemployment and money, with explicit microeconomic foundations. We show that the implied relation between inflation and unemployment can be positive or negative, depending on simple preference conditions. Our Phillips curve provides a long‐run, exploitable, trade‐off for monetary policy; it turns out, however, that the optimal policy is the Friedman rule.     

Monte Carlo Evaluation of Greeks for Multidimensional Barrier and Lookback Options

In this paper, we consider the problem of the numerical computation of Greeks for a multidimensional barrier and lookback style options: the payoff function depends in a rather general way on the minima and maxima of the coordinates of the d -dimensional underlying asset process. Using Malliavin calculus techniques, we derive additional weights that enable computation of the Greeks using Monte Carlo simulations. Numerical experiments confirm the efficiency of the method. This work is a multidimensional extension of previous results (see Gobet and Kohatsu-Higa 2001 ).     

A Market Efficiency Comparison of Islamic and Non-Islamic Stock Indices

This article examines the martingale difference hypothesis (MDH) and the random walk hypothesis (RWH) for nine conventional and nine Islamic stock indices: Asia-Pacific, Canadian, Developed Country, Emerging, European, Global, Japanese, UK, and United States. It investigates whether Islamic stock indices are more, less, or as efficient as their conventional counterparts. We test four sub-periods of bullish and bearish stock markets, together with the financial meltdown and its recovery, over the period 1997–2012. We use the Escanciano and Lobato’s (2009) automatic portmanteau test (AQ) and Deo’s (2000) test for the MDH. We also apply the automatic variance ratio test (AVR) developed by Choi (1999) and Kim (2009) for the RWH. Over the period from 1997 to 2012, we find that three conventional indices (Europe, Japan, and UK) are efficient, but that none of the Islamic indices are efficient in these markets. During the recent financial crisis, our results indicate slightly more efficiency for the Islamic indices than their conventional counterparts. Our study finds that overall the conventional indices are more efficient than their Islamic counterparts. Nevertheless, during periods of general downturns the Islamic indices have shown the same level of efficiency as their counterparts. Furthermore, it appears that during the last two sub-periods under study, the Islamic indices have moved toward efficiency, displaying the same level of efficiency as their counterparts.