Boucekkine
Publications
This paper revisits the optimal population size problem in a continuous time Ramsey setting with costly child rearing and both intergenerational and intertemporal altruism. The social welfare functions considered range from the Millian to the Benthamite. When population growth is endogenized, the associated optimal control problem involves an endogenous effective discount rate depending on past and current population growth rates, which makes preferences intertemporally dependent. We tackle this problem by using an appropriate maximum principle. Then we study the stationary solutions (balanced growth paths) and show the existence of two admissible solutions except in the Millian case. We prove that only one is optimal. Comparative statics and transitional dynamics are numerically derived in the general case.
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).
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After years of high commodity prices, a new era of lower ones, especially for oil, seems likely to persist. This will be challenging for resource-rich countries, which must cope with the decline in income that accompanies the lower prices and the potential widening of internal and external imbalances. This column presents a new VOXEU eBook in which leading economists from academia and the public and private sector examine the shifting landscape in commodity markets and look at the exchange rate, monetary, and fiscal options policymakers have, as well as the role of finance, including sovereign wealth funds, and diversification.
This paper aims at clarifying the analytical conditions under which financial globalization originates welfare gains in a simple endogenous growth setting. We focus on an open-economy AK model in which the capital-deepening effect of financial globalization boosts growth in a in permanent but entails an entry cost in order to access international credit markets. We show that constrained borrowing triggers substantial welfare gains, even at small levels of international financial integration, provided that the autarkic growth rate is larger than the world interest rate. Such conditional welfare benefits boosted by stronger growth—long-run gain—arise in our preferred model without investment commitment and they range, relative to autarky, from about 2% in middle-income countries to about 13% in OECD-type countries under international financial integration. Sizeable benefits emerge despite the fact that consumption initially falls—short-run pain—which is, however, shown not to dwarf positive growth changes.
Two countries produce goods and are penalized by the common pollution they generate. Each country maximizes an inter-temporal utility criterion, taking account of the pollution stock to which both contribute. The dynamic is in continuous time with possible sudden switches to less polluting technologies. The set of Nash equilibria, for which solutions also remain in the set of constraints, is the intersection of two manifolds in a certain state space. At the Nash equilibrium, the choices of the two countries are interdependent: different productivity levels after switching lead the more productive country to hasten and the less productive to delay the switch. In the absence of cooperation, efforts by one country to pollute less motivate the other to pollute more, or encourage the country that will be cleaner or less productive country after switching to delay its transition.
The mechanism stating that longer life implies larger investment in human capital, is premised on the view that individual decision-making governs the relationship between longevity and education. This relationship is revisited here from the perspective of optimal period school life expectancy, obtained from the utility maximization of the whole population characterized by its age structure and its age-specific fertility and mortality. Realistic life tables such as model life tables are mandatory, because the age distribution of mortality matters, notably at infant and juvenile ages. Optimal period school life expectancy varies with life expectancy and fertility. The application to French historical data from 1806 to nowadays shows that the population age structure has indeed modified the relationship between longevity and optimal schooling.
Measuring direct and indirect effects of extending health insurance coverage in developing countries is a key issue for health system development and for attaining universal health coverage. This paper investigates the role played by health insurance in the relationship between parental morbidity and child work decisions. We use a propensity score matching technique combined with hurdle models, using data from Rwanda. The results show that parental health shocks have a substantial influence on child work when households do not have health insurance. Depending on the gender of the sick parent, there is a substitution effect not only between the parent and the child on the labor market, but also between the time the child spends on different work activities. Altogether, results reveal that health insurance protects children against child work in the presence of parental health shocks.
This note introduces to the literature streams explored in the special section on international financial markets and banking systems crises. All topics tackled are related to the Great Recession. A brief overview of the research questions and related literatures is provided.
This paper introduces variable markups in a horizontal-differentiation growth model by considering a larger class of preferences that nests the classic “CES” specification usually present in the workhorse love-for-variety models. Our first result is to obtain a generalized characterization of the Euler condition for this broader class of utility functions: in our model, the Euler rule features a supplementary term aiming at compensating the consumer for variations in the preference for variety along the consumption level. We are then also able to demonstrate that in our generalized framework, the economy’s balanced growth path displays both endogenous markups and a strictly positive growth rate of the number of available varieties (being the engine of growth). Finally, we show that under endogenous markups, the economy’s growth rate and firms’ market power can display a negative correlation, as opposed to the standard result obtained in the CES framework.