We quantify the importance of endogenous human capital and of selection effects for counterfactual analysis of social security (SS) reforms. The literature typically performs these analyses by using structural models featuring exogenous productivity profiles. However, this approach faces two issues: (i) the estimation of productivity is subject to selection bias, and (ii) productivity is endogenous to the SS reforms. In this paper, we estimate a quantitative overlapping generations model featuring endogenous human capital accumulation using US data. First, we eliminate the SS and find a large positive effect on aggregate effective labor supply (${+}10.31\%$). Next, we build variants of this model to quantify the two issues (i) and (ii). We find that the endogeneity issue (ii) is quantitatively more important than the selection bias issue (i).

We study whether the increased adoption of available automation technologies allows economies to avoid the negative effect of aging on per capita output. We develop a quantitative theory in which firms choose to which extent they automate in response to a declining workforce and rising old-age dependency. An important element in our model is the integration of two capital types: automation capital that acts as a substitute to human labor, and traditional capital that is a complement to labor. Empirically, our model's predictions largely match data regarding automation (robotization) density across OECD countries. Simulating the model, we find that aging-induced automation only partially compensates the negative growth effect of aging in the absence of technical progress in automation technology. One reason is that automated tasks are no perfect substitutes for non-automated tasks. A second reason is that automation raises the interest rate and thus inhibits positive behavioral reactions to aging (later retirement and investment in human capital). Moreover, increased automation generates a falling net labor share of income and rising welfare inequality. We evaluate alternative policy responses to cope with this inequality.

The rapid development of the digital economy has highlighted the crucial role of data in economic growth. This study investigates the impact of two types of innovation on long-term growth by incorporating data into a model of creative destruction and knowledge accumulation. Unlike traditional factors, data exhibit nonrivalry between the two research and development (R&D) sectors, thereby influencing the growth rate of economic outputs simultaneously without interference. Our findings reveal the existence of a balanced growth path (BGP) in both the decentralized economy and the social planner’s economy. In horizontal innovation, data can be transformed into digital knowledge to promote the economic growth [Cong et al. (2021)]. In addition to horizontal innovation, the utilization of data in vertical innovation also enhances the success rate of innovation, with a gradual decrease in per capita data usage on the BGP. Moreover, as agents accumulate human capital, the economy achieves higher output levels, effectively addressing consumer privacy concerns. However, along the transitional path, insufficient data provision by both R&D sectors leads to lower economic growth rates or more intense economic fluctuations, necessitating policy interventions.

I develop a dynamic model of consumption variety in status goods by introducing a realistic aspect that is new in the existing literature—that a good will not carry status appeal unless it is advertised. As advertisements will divert resources from new product research, growth in new products will be reduced. However, status-good advertisements also enhance distinctiveness of a good and increase a firm’s profit. This will motivate more researches. With the two effects offsetting each other, the original market bias in a standard product-development model—insufficient research due to a general knowledge spillover—cannot be overcome. While introducing advertising into models of this kind does not reverse the original welfare implication of suboptimal growth, this makes available a new and better intervention option—taxing advertisements. This tax is superior to consumption tax, the conventional solution to inefficient status competition, as consumption tax is found to be ineffective in the present model. It is also superior to research subsidies, the conventional solution to suboptimal growth, as subsidies must be financed and is not a self-sufficient policy.

We present a multiregional endogenous growth model in which forward-looking agents choose their regions to live in, in addition to consumption and capital accumulation paths. The spatial distribution of economic activity is determined by the interplay between production spillover effects and urban congestion effects. We characterize the global stability of the spatial equilibrium states in terms of economic primitives such as agents’ time preference and intra- and interregional spillovers. We also study how macroeconomic variables at the stable equilibrium state behave according to the structure of the spillover network.

Advanced economies undergo three transitions during their development: (1) transition from a rural to an urban economy, (2) transition from low-income growth to high-income growth, (3) transition from high fertility and mortality rates to low modern levels. The timings of these transitions are correlated in the historical development of most advanced economies. I consider a nonlinear model of endogenous long-run economic and demographic change, in which child quantity-quality substitution is driven by declining child mortality. Because the model captures the interactions between all three transitions, it is able to explain three additional empirical patterns: a declining urban-rural wage gap, a declining rural-urban family size ratio, and most surprisingly, that early urbanization slows development. This third prediction distinguishes the model from other theories of long-run growth, and I document evidence for it in cross-country data.

According to the conventional theory of the demographic transition, mortality decline has represented the major trigger of fertility decline and sustained economic development. In Sub-Saharan Africa (SSA), the HIV/AIDS epidemic has had a devastating impact on mortality, dramatically reversing the long-term positive trend in life expectancies in high HIV-prevalence countries. Moreover, SSA is experiencing a delayed and slower fertility transition compared to other world regions and there is growing empirical evidence highlighting the potential for a paralysis, or even a reversal, of the fertility transition in countries with severe HIV epidemics. This work builds on a unified growth theory-like general equilibrium model combined with HIV spread, where mortality endogenously feeds back into fertility and education decisions. The model supports the evidence of an HIV-triggered fertility reversal in SSA via the fall in education and human capital investments due to increased adult mortality, which eventually breaks the switch from quantity to quality of children. Fertility reversal is predicted to be more likely to occur in countries experiencing severe HIV epidemics, and its effects may persist even under successful scenarios of HIV control. These results suggest that the alarming possibility of a paralysis in the fertility transition, which so far has aroused little concern among international organizations, e.g., in the last round of UN population projections, should be seriously considered with a view to prioritizing policy interventions.

This article analyzes a general equilibrium growth model with overlapping generations and (production-induced) environmental degradation. Individuals react to environmental damages through mitigation or adaptation. In the former case, they reduce production and its environmental impact. In the latter, they do not tackle the causes of the problem but rather its consequences (i.e., the wellbeing loss due to environmental degradation) by increasing defensive expenditures. Despite its simplicity, the model can generate different long-term outcomes: convergence to a stationary state following a unique trajectory or local/global indeterminacy. In the last scenario, initial conditions (history) and individual expectations matter and the model can generate coordination failures and endogenous fluctuations. Results cast doubt on solutions to environmental problems relying on the role of individual behavior change or adaptation.

Environmental economics models are often too complex to be communicated in an illustrative manner. For this reason, this paper develops the Basic Climate Economic (BCE) model that features core elements of macroeconomic and climate economic modelling, while allowing for an illustrative examination of the development path. The BCE model incorporates fossil stock depletion, pollution stock accumulation, endogenous growth, and climate-induced capital depreciation. We first use graphical analysis to show the effects of climate change and climate policy on economic development. Intuition for the different model mechanisms, the functional forms, and the effects of different climate policies is provided. We then show the model equations in mathematical terms to derive closed-form solutions and to run model simulations relating to the graphical part. Finally, we compare our setup to other models of climate economics.

The aim of the paper is to investigate how child policies affect the population growth and to what extent these policies are useful to increase pension benefits of a pay-as-you-go pension system in a small open economy. Specifically, we analyze two different child policies: the provision of child allowances and an educational subsidy. We apply an overlapping generations model in its canonical form, where we consider endogenous fertility, endogenous growth and endogenous aging of the society. From the analysis, we conclude that with a child allowance, there is a consequent increase in the number of children and decrease in pension benefits and life expectancy. On the other hand, we note that with an educational subsidy, there is a decrease in the number of children, and an increase in the pension benefits and the life expectancy, respectively. The model developed aims to complement the models of the Unified Growth Theory.

The process of structural transformation from the farm to a nonfarm sector is accompanied by technological change in both sectors and massive population growth. We investigate the effects of increasing population size (the population effect) and sector-specific productivity (the push and pull effects), both factor-neutral and factor-biased, in a parsimonious general equilibrium model under general forms of utility and production functions. All three effects may co-exist and interact in important ways. Generalizing the agricultural sector production function to CES is crucial for the population growth effect. Our analysis highlights how the relative importance of the three effects changes as the country develops and production and consumption conditions become more flexible.

The UK, with its relatively liberal immigration policies following recent enlargements, has been one of the main recipients of migrants from new EU member states. This paper poses the questions: what is the effect of immigration on a receiving economy such as the UK? Is the effect beneficial or adverse for growth? Does emigration have brain drain effects on sending economies? How differently would skilled (or unskilled) migration affect both receiving and sending economies? What factors would contribute to immigration/emigration benefits/costs and economic growth driven by migration? Who are the winners and losers in both the sending and host regions? We utilise a two-bloc endogenous growth model with labour mobility of different skill compositions to address these questions. We show that migration, in general, is beneficial to the receiving country and increases the world growth rate. With remittances, the sending country in aggregate can also benefit. The only exception is in the case of unskilled migration, which can actually have a detrimental impact on the world growth rate. This possibility however seems to be unlikely by our examination of migration trends. Winners are migrants, and the skill group in the region that sees its relative size decrease.

According to AK growth models, permanent changes in investment rates have permanent effects on a country's rate of economic growth. Jones (Quarterly Journal of Economics, 1995, 110, 495-525) finds strong evidence against this prediction studying the time series properties of GDP growth rates and investment output ratios in fifteen OECD countries for the period 1950-1988. In this paper, we test the same hypothesis in four OECD countries using a longer span of data (1870-2002 for Canada, the UK and the US, and 1885-2002 for Japan). Moreover, instead of using classic approaches, which are based on stationary I(0) or unit roots I(1) processes, we use methodologies based on fractional integration. After examining the order of integration of GDP growth rates and non-residential investment ratios for these countries, we do not find much evidence against the “growth effects” prediction of AK models. In fact, we only find clear evidence against this theory for the UK case.

This article examines the real convergence hypothesis in eleven emerging countries by means of fractionally integrated techniques. For this purpose, we examine the order of integration of the real GDP per capita series in Argentina, Brazil, Chile, Colombia, Mexico, Peru, Venezuela, India, Indonesia, Taiwan and South Korea as well as their differences with respect to the US and Japan. We find evidence of smaller degrees of integration in the differenced series only for some of the Latin American countries with respect to the US, and for all the Asian countries with respect to both the US and Japan. However, we only find evidence of real convergence for the cases of Argentina and Chile with respect to the US, and Taiwan with respect to Japan, suggesting thus the possibility of different convergence clubs among both Latin American and Asian countries.

New U.S. evidence from NIPA contradicts some of the well-known Kaldor stylized facts, and call for a reformulation of the modern theory of economic growth. Among these new facts, two must be stressed: A permanent decline in the relative price of durable goods, and a permanent increase in the real equipment to real GDP ratio. To be consistent with these new facts, growth models must include at least two sectors and address the problem of defining aggregate output. In this paper, the economic theory of index numbers is used to define the growth rate of real output in a growth model with embodied technical change. The main findings are: (i) NIPA’s methodology measures growth in accordance with the economic theory on index numbers, and (ii) when the growth rate is measured as in NIPA, the contribution of embodied technical change to per capital GDP growth in the U.S. is 69%, which reinforce the claim that embodied technical change is important for growth.

This contribution illustrates the role of an imperfectly competitive process of capital accumulation in the growth process. It emphasizes the central role of investment in long-run outcomes. Whereas the final good sector is characterized by perfect competition, temporary monopolies take place in the capital goods ones. These monopolies rest on an increasing returns property in the production technology that in turn results from dynamic intrasectoral externalities. The model is characterized by a sustained long-run growth path at a constant rate. This solution departs from the ones that have emerged in the recent literature because the growth rate of the capital stock and the growth rate of knowledge are not identical.

Nous considérons un modèle à générations imbriquées en économie fermée avec des travailleurs qualifiés et des travailleurs non qualifiés. Il existe un système de retraite obligatoire qui se décompose en deux branches: une branche avec financement par répartition, cotisations proportionnelles aux salaires et prestations uniformes et une branche basée sur le double principe de la capitalisation et de la commutati-vité. Nous étudions la solution optimale stationnaire choisie par un planificateur qui maximise un critère de bien-être social utilitariste. Nous montrons que, si l'économie sans système de retraite est en sous-accumulation mais pas trop éloignée de la règle d'or ou en suraccumulation, il est optimal d'introduire les deux systèmes.