Publications
We compare how the long-run distribution of fishing activities is affected in multispecies fisheries when facing different second-best control rules: (1) species-specific landing regulation, and (2) global input regulation. We show how this depends on the economic returns and on the type of ecological interaction considered. We highlight specifically that fishing effort does not necessarily increase on nontargeted species and decrease on targeted species, and that the characterization of second-best efficient instruments may differ drastically depending on the nature of the interaction.
This paper proposes a new model with time-varying slope coefficients. Our model, called CHAR, is a Cholesky-GARCH model, based on the Cholesky decomposition of the conditional variance matrix introduced by Pourahmadi (1999) in the context of longitudinal data. We derive stationarity and invertibility conditions and prove consistency and asymptotic normality of the Full and equation-by-equation QML estimators of this model. We then show that this class of models is useful to estimate conditional betas and compare it to the approach proposed by Engle (2016). Finally, we use real data in a portfolio and risk management exercise. We find that the CHAR model outperforms a model with constant betas as well as the dynamic conditional beta model of Engle (2016).
On a French firm dataset, productivity at the technological frontier has not decelerated and convergence of firms’ productivity has not slowed down. Yet, the dispersion of productivity has increased, which suggests growing difficulties in reallocating production factors between firms.
This paper features a growth model with an appropriative contest and a common-pool investment game between politically organised rival ethnic factions. I determine how the long-run equilibrium coalition shapes incentives to invest, show the existence of a unique steady state, and investigate how the ease to capture rents affects economic performance. The use of numerical simulations concerning a global sample of countries demonstrates that contest intensity can sometimes be beneficial, despite wasteful grabbing behaviours, due to a mechanism related to the concentration of power. When rents become easier to capture, dominant groups have an incentive to expand their influence further. This adjustment can be beneficial as these groups contribute most to capital accumulation.
Constraints that prevent women from working longer hours are argued to be important drivers of the gender wage gap in the United States. We provide evidence that in couples where the wife's working hours exceed the husband's, the wife reports lower life satisfaction. By contrast, there is no effect on the husband's satisfaction. The results still hold when controlling for relative income. We argue that these patterns are best explained by perceived fairness of the division of household labor, which induces an aversion to a situation where the wife works more at home and on the labor market.
Under uncertainty, mean growth of, say, wealth is often defined as the growth rate of average wealth, but it can alternatively be defined as the average growth rate of wealth. We argue that stochastic stability points to the latter notion of mean growth as the theoretically relevant one. Our discussion is cast within the class of continuous-time AK-type models subject to geometric Brownian motions. First, stability concepts related to stochastic linear homogeneous differential equations are introduced and applied to the canonical AK model. It is readily shown that exponential balanced-growth paths are not robust to uncertainty. In a second application, we evaluate the quantitative implications of adopting the stochastic-stability-related concept of mean growth for the comparative statics of global diversification in the seminal model due to Obstfeld (1994).
We investigate the extent to which standard one sector RBC models with positive externalities and variable capacity utilization can account for the large hump-shaped response of output when the model is submitted to a pure sunspot shock. We refine the Benhabib and Wen (2004) model considering a general type of additive separable preferences and a general production function. We provide a detailed theoretical analysis of local stabilities and local bifurcations as a function of various structural parameters. We show that, when labor is infinitely elastic, local indeterminacy occurs through Flip and Hopf bifurcations for a large set of values for the elasticity of intertemporal substitution in consumption, the degree of increasing returns to scale and the elasticity of capital–labor substitution. Finally, we provide a detailed quantitative assessment of the model and conclude with mixed results. We show that although the model is able theoretically to generate a hump-shaped dynamics of output following an i.i.d. sunspot shock under realistic parameter values, the hump is too persistent for the model to be considered fully satisfactory from an empirical point of view.
In 2002, the Israeli government decided to build a wall inside the occupied West Bank. The wall had a marked effect on the access to land and water resources as well as to the Israeli labour market. It is difficult to include the effect of the wall in an econometric model explaining poverty dynamics as the wall was built in the richer region of the West Bank. So a diff-in-diff strategy is needed. Using a Bayesian approach, we treat our two-period repeated cross-section data set as an incomplete data problem, explaining the income-to-needs ratio as a function of time invariant exogenous variables. This allows us to provide inference results on poverty dynamics. We then build a conditional regression model including a wall variable and state dependence to see how the wall modified the initial results on poverty dynamics. We find that the wall has increased the probability of poverty persistence by 58 percentage points and the probability of poverty entry by 18 percentage points.
This paper shows that a large dimensional vector autoregressive model (VAR) of finite order can generate fractional integration in the marginalized univariate series. We derive high-level assumptions under which the final equation representation of a VAR(1) leads to univariate fractional white noises and verify the validity of these assumptions for two specific models.
To expedite payments, firms use convenience pricing strategies. A price is considered convenient if it can be paid with few coins. Convenient prices are well understood in offline retailing, but not online. This article fills the gap, examining an original panel dataset more than 2.5 million observations of book prices from Amazon.com. We provide empirical evidence supporting two claims. First in a static setup, more convenient prices are more likely to be set. Second in a dynamic setup, more convenient prices are more rigid. Emphasizing the role of convenience, this work sheds new light on price setting in online retailing.
