Optimal investment models with vintage capital: Dynamic programming approach

The dynamic programming approach for a family of optimal investment models with vintage capital is here developed. The problem falls into the class of infinite horizon optimal control problems of PDE’s with age structure that have been studied in various papers (12, 11, 33 and 35) either in cases when explicit solutions can be found or using Maximum Principle techniques.     

Quasi‐fixed inputs and long‐run equilibrium in production: a cointegration analysis

This paper proposes a cointegration approach to testing the validity long‐run equilibrium in production, where capital and labour are taken as quasi‐fixed inputs. Previous studies consider only capital as the quasi‐fixed input and do not take account of the time series properties of the variables, assuming implicitly that they are stationary. The canonical cointegrating regressions (CCR) procedure is employed to test for cointegration in both the single‐equation and the seemingly unrelated regressions framework, and long‐run equilibrium conditions are tested. The evidence from US manufacturing reveals that capital and labour are not fully adjusted to their long‐run optimal values, casting doubt on the long‐run equilibrium hypothesis. Copyright © 2001 John Wiley & Sons, Ltd.     

An optimal multiple stopping approach to infrastructure investment decisions

The energy and material processing industries are traditionally characterized by very large-scale physical capital that is custom-built with long lead times and long lifetimes. However, recent technological advancement in low-cost automation has made possible the parallel operation of large numbers of small-scale and modular production units. Amenable to mass-production, these units can be more rapidly deployed but they are also likely to have a much quicker turnover. Such a paradigm shift motivates the analysis of the combined effect of lead time and lifetime on infrastructure investment decisions. In order to value the underlying real option, we introduce an optimal multiple stopping approach that accounts for operational flexibility, delay induced by lead time, and multiple (finite/infinite) future investment opportunities. We provide an analytical characterization of the firm׳s value function and optimal stopping rule. This leads us to develop an iterative numerical scheme, and examine how the investment decisions depend on lead time and lifetime, as well as other parameters. Furthermore, our model can be used to analyze the critical investment cost that makes small-scale (short lead time, short lifetime) alternatives competitive with traditional large-scale infrastructure.     

资本体现式技术进步、技术合意结构和我国生产率增长来源

本文基于动态前沿生产面的非参数方法获取分行业全要素生产率指数,依据资本体现式技术进步发展耦合于蕴涵前沿技术的机器设备投资过程逻辑,以分行业固定资产投资中的设备工器具投资表征资本体现式技术进步,通过面板数据回归检验不同类型技术进步及其匹配结构对我国制造业生产率的影响。结果显示:资本体现式技术进步是生产率增长的重要来源,但技术效率实现与否内嵌于经济环境,受制于行业利润率及技术与人力资本的匹配程度。行业整体合意技术结构效应不明显,而以利润率和国有化程度分组发现,高国有化行业和高利润率行业存在合意技术结构。     

Contribution of female human capital in economic growth: an empirical analysis of Pakistan (1972–2012)

This study is to find out an impact of female human capital on economic growth of Pakistan. The study has therefore, used gender separate human capital as an explanatory variable along with other factors, labor force and physical capital. In this regard a composite human capital has been constructed by taking education and health as a proxy for human capital. The long run and short run dynamics among female human capital and economic growth are empirically tested on time series data spread from 1972–2012. Johanson’s co-integration approach has been applied for the long run and Vector Error Correction Model used for the short run relationship. The results show that the long run relationship between female human capital and economic growth is positive and significant. While the short run impact of female human capital on economic growth is positive but statistically insignificant.     

An endogenous growth cycle with vintage capital

This paper extends Solow's vintage capital model by (a) deriving profits as a function of investments, and (b) adding an investment financing equation in terms of profits. It is shown that these extensions lead to a completely endogenous growth model. The dynamic system yields an equilibrium which is a centre and hence the economy cycles perpetually around the equilibrium point, never reaching it.     

Foreign capital inflows and economic growth of Pakistan

This study investigates the relationship of foreign capital inflows, namely foreign direct investment, workers’ remittances, and external debt with economic growth of Pakistan by employing time series data from 1976 to 2015. Cointegration results indicate that foreign capital inflows and economic growth have a significant relationship with economic growth in the long run. Ordinary least square results indicate foreign direct investment has a significant and negative effect on economic growth, whereas a significant positive effect of remittances and external debts on economic growth is found. Rolling windows analysis highlights the yearly effect of three different models. Two different sensitivity analyses confirmed that initial results are robust. The final section concludes the study and provides some policy implications.     

Optimal agglomerations in dynamic economics

We study rational expectations equilibrium problems and social optimum problems in infinite horizon spatial economies in the context of a Ramsey type capital accumulation problem with geographical spillovers. We identify sufficient local and global conditions for the emergence (or not) of optimal agglomeration, using techniques from monotone operator theory and spectral theory in infinite dimensional Hilbert spaces. We show that agglomerations may emerge, with any type of returns to scale (increasing or decreasing) and with the marginal productivity of private capital increasing or decreasing with respect to the spatial externality. This is a fairly general result indicating the importance of the network structure of the spatial externality relative to the properties of the aggregate production function. Our analytical methods can be used to systematically study optimal potential agglomeration and clustering in dynamic economics.     

Non‐linear Dynamics in the Infinite Time Horizon Model

Using results from the theory of non‐linear dynamical systems, it has been shown that optimal growth theory can provide new explanations for business cycles and for international differences in growth and development. The present survey concentrates on this aspect of optimal growth theory, that is on the possibility of fluctuations and non‐uniqueness in models of optimal capital accumulation. It is a selective survey on non‐linear dynamics in infinite time horizon models of optimal growth.     

On the smoothness of optimal paths II: some local turnpike results

We study the local turnpike property for two classes of infinite-horizon discrete-time deterministic maximization problems which have common applications, e.g., optimal growth theory. We follow a functional-analytic approach and rely on an implicit function theorem for the space of the sequences which converge to zero. We shall assume the existence of an optimal path which is not necessarily a steady-state. Relying on material developped in Blot and Crettez (Decis Econo Finance 27:1–34, 2004), “On the smoothness of optimal paths” Decis Econ Finance, 21:1–34, 2004), we provide conditions under which a variation in the initial conditions (i.e., capital stock and discount rate) yields an optimal solution which converges toward a reference solution when time becomes infinite. We also provide new results on bounded solutions of difference equations. We gratefully thank the editor, Silvano Holzer, and two anonymous referees for remarks and advices on a previous version of this paper.     

突发大规模疫情对经济发展的影响 ——基于公众关注和媒体关注的视角

本文基于疫情风险影响经济增长的理论模型，发现消费、投资的变化不但取决于疫情对全要素生产率、资本存量等供给因素的影响，也受到需求因素的影响。然后基于公众关注和媒体关注的视角，采用网络搜索量进行量化，运用NARDL模型研究大规模疫情冲击对经济的长短期非对称传导效应。实证结果表明：短期内，公众和媒体对疫情的关注增加对经济发展的负向冲击明显更强；长期内，公众关注和媒体关注对经济发展负向影响较为有限，经济较快恢复稳态增长水平；公众和媒体对疫情关注的增加和减少对不同经济类型企业和不同行业的影响有所不同。基于此，本文建议以财政政策为主，以结构性货币政策为辅，保证信息公开及时，采用结构性和差异化策略精准滴灌支持中小企业复工复产，避免资金链、产业链和供应链断裂，确保经济企稳恢复。     

Foreign capital inflows, economic growth and stock market capitalization in Asian countries: an ARDL bound testing approach

This study investigates the effects of foreign capital inflows and economic growth on stock market capitalization in 18 Asian countries by using the panel data from the period of 2000–2010. The ARDL bound testing cointegration approach confirms the valid long run relationship between the considered variables. Results indicate that foreign direct investment has significant negative and economic growth has significant positive relationship with the stock market capitalization, whereas, the results of workers’ remittances is found insignificant in long run. The error correction model confirms the significant positive relationship of economic growth and workers’ remittances while, FDI has negative and significant impact on stock market capitalization in short run. Results of causality test based on Toda and Yamamoto (J Econom 66: 225–250, 1995) show the bidirectional causal relationship of foreign direct investment and economic growth with stock market capitalization. However, no causal relationship is found in between workers’ remittances and stock market capitalization. It is suggested that investor should not idealize the inflow of workers’ remittances to invest in Asian stock markets in long run. Simultaneously, size of the economy is a better leading indicator for Asian stock markets. On the other hand, inflows of FDI may mislead the investor to invest. Investor should keep on eye whether FDI come in the competition of domestic market or not? If this happens so investor should not invest in the stock market of host country.     

Spatial agglomeration and endogenous growth

This paper constructs a dynamic general equilibrium model with spatial interactions in which a human capital externality is the centripetal force towards agglomeration. The resource cost of transportation is, on the other hand, the main centrifugal force, preventing a city from growing unboundedly. A central feature of our analysis is the dynamic interaction between (perpetual) economic growth and (bounded) city growth. We examine the socially optimal and the decentralized growth rates as well as city sizes. In the decentralized environment, individuals under-invest, whereas cities are under-populated. We show how public policies may enable a decentralized city to attain the socially optimal allocation.     

Incentive compatibility constraints and dynamic programming in continuous time

This paper is devoted to the study of infinite horizon continuous time optimal control problems with incentive compatibility constraints that arise in many economic problems, for instance in defining the second best Pareto optimum for the joint exploitation of a common resource, as in Benhabib and Radner [Benhabib, J., Radner, R., 1992. The joint exploitation of a productive asset: a game theoretic approach. Economic Theory, 2: 155–190]. An incentive compatibility constraint is a constraint on the continuation of the payoff function at every time. We prove that the dynamic programming principle holds, the value function is a viscosity solution of the associated Hamilton–Jacobi–Bellman (HJB) equation, and that it is the minimal supersolution satisfying certain boundary conditions. When the incentive compatibility constraint only depends on the present value of the state variable, we prove existence of optimal strategies, and we show that the problem is equivalent to a state constraints problem in an endogenous state region which depends on the data of the problem. Some economic examples are analyzed.     

Dealing with Benchmark Revisions in Real‐Time Data: The Case of German Production and Orders Statistics*

Benchmark revisions in non‐stationary real‐time data may adversely affect the results of regular revision analysis and the estimates of long‐run economic relationships. Cointegration analysis can reveal the nature of vintage heterogeneity and guide the adjustment of real‐time data for benchmark revisions. Affine vintage transformation functions estimated by cointegration regressions are a flexible tool, whereas differencing and rebasing work well only under certain circumstances. Inappropriate vintage transformation may cause observed revision statistics to be affected by nuisance parameters. Using real‐time data of German industrial production and orders, the econometric techniques are exemplified and the theoretical claims are examined empirically.     

The relationship between trade,FDI and economic growth in Tunisia: An application of the autoregressive distributed lag model

The relationship between foreign direct investment (FDI), trade openness and economic growth in host countries remains one of the most important issues in the economic literature and met with renewed interest in recent years mainly for countries suffering from unemployment problems and lack of technological progress. This paper examines this issue for Tunisia by applying the bounds testing (ARDL) approach to cointegration for the period from 1970 to 2008. The bounds tests suggest that the variables of interest are bound together in the long run when foreign direct investment is the dependent variable. The associated equilibrium correction is also significant, confirming the existence of a long-run relationship. The results also indicate that there is no significant Granger causality from FDI to economic growth, from economic growth to FDI, from trade to economic growth and from economic growth to trade in the short run. Even though there is a widespread belief that FDI can generate positive spillover externalities for the host country, our empirical results fail to confirm this belief for the case of Tunisia. They go against the generally accepted idea considering the positive impact of FDI on economic growth to be automatic. The results found for Tunisia can be generalized and compared to other developing countries which share a common experience in attracting FDI and trade liberalization.     

Owner-occupied housing in a model of exchange rate determination

This study explores the effect of owner-occupied housing asset holdings on the short and long run determination of exchange rates. In the presence of consumption goods that can simultaneously serve as investment allocation subject to capital gains—such as owner-occupied housing—the general equilibrium model, based on the Obstfeld and Rogoff Redux model, produces exchange rate overshooting both in the presence and in the absence of price rigidities in the markets for final goods. This effect depends on the size of owner-occupied housing expenditures relative to total consumption expenditures, the initial level of housing market inflation, capital gains in housing and other parameters of the model. Depending on parameter values and initial conditions, the model supports the possibility for exchange rate dynamics that include either overshooting or undershooting.     

Explicit investment rules with time-to-build and uncertainty

We establish explicit socially optimal rules for an irreversible investment decision with time-to-build and uncertainty. Assuming a price sensitive demand function with a random intercept, we provide comparative statics and economic interpretations for three models of demand (arithmetic Brownian, geometric Brownian, and the Cox–Ingersoll–Ross). Committed capacity, that is, the installed capacity plus the investment in the pipeline, must never drop below the best predictor of future demand, minus two biases. The discounting bias takes into account the fact that investment is paid upfront for future use; the precautionary bias multiplies a type of risk aversion index by the local volatility. Relying on the analytical forms, we discuss in detail the economic effects. For example, the impact of volatility on the optimal investment is negligible in some cases. It vanishes in the CIR model for long delays, and in the GBM model for high discount rates.     

On the role of labor supply for the optimal size of Social Security

The paper studies the welfare effects of a Social Security system in a stylized overlapping generations economy with random production and capital accumulation. Different welfare concepts including long run optimality, social optimality, and time consistency are employed to determine the optimal size of the system. When labor supply is exogenous, a unique contribution level can be identified which is optimal according to all three concepts. When labor supply is endogenous, however, this result generically fails to hold and the long-run optimal solution is only constrained socially optimal while the time-consistent policy may even lead to an inefficient equilibrium.     

Ramsey policies in a small open economy with sticky prices and capital

This paper analyzes jointly optimal fiscal and monetary policies in a small open economy with capital and sticky prices. We allow for trade in consumption goods under perfect international risk-sharing. We consider balanced-budget fiscal policies where authorities use distortionary taxes on labor and capital together with monetary policy using the nominal interest rate. First, as long as a symmetric equilibrium is considered, the steady state in an open economy is isomorphic to that of a closed economy. Second, sticky prices’ allocations are almost indistinguishable from flexible prices allocations both in open and closed economies. Third, the open economy dimension delivers results that are qualitatively similar to those of a closed economy but with significant quantitative changes. Tax rates are both more volatile and more persistent to undo the distortions implied by terms of trade fluctuations.