Global indeterminacy and equilibrium selection in a model with depletion of non-renewable resources

We use the principles of global bifurcation analysis to explore the role of fiscal policy in a model where non-renewable depletion presents stock effects. Initially, we show that fiscal policy may induce the onset of two coexisting steady states, one of which is characterized by a lower depletion rate and higher income (virtuous steady state) than the other (bad steady state). Then, we shed light on the ability of an endogenous fiscal policy to act as an equilibrium selection device. We find that when the economy is sufficiently patient and exhibits low capital returns and environmental parameters, fiscal policy can create a continuum of equilibria that leads to the virtuous steady state. In the opposite situation of an impatient economy, which has high capital returns and environmental parameters, fiscal policy can only create one perfect-foresight path (a heteroclinic trajectory) through which the economy can approach the virtuous steady state.     

Roles of Public Capital in Pakistan's Economy: Productivity, Investment and Growth Analysis

This study analyzes the role of public capital in Pakistan's economy, tracing the relationship between productivity of public capital and economic growth. We estimate a production function, with public capital as an inputs. The results indicate that the productivity (output elasticity) of aggregate as well as different components of public capital are sufficiently high. We also analyze substitutability and complementarity between public and private capital by estimating investment functions, revealing that public capital has worked as a substitute for private investment. The net effect of public capital on the national economy is analyzed by estimating reduced forms, with the result that public capital has a positive net effect on national product. The growth analysis shows that the contribution of public capital is declining over time.     

Expansionary effects of the welfare state in a small open economy

We examine the relationship between welfare state policies and economic performance in a small open economy with (i) free trade in final goods and international capital mobility, and (ii) aggregate increasing returns to scale. Contrary to the conventional wisdom, we find that a retrenchment of welfare programmes is not an inevitable consequence of economic integration. Instead, by improving the exploitation of aggregate scale economies, social expenditure policies and international openness complement each other in facilitating an improvement in economic performance that can sustain a more generous welfare protection.     

Cities in Contemporary Capitalism

This article outlines essential concepts of the political economy approach of urban research and offers critical modifications and clarifications to some of its contentions concerning the functioning of cities as ‘strategic places’ of capital accumulation. The interrelations between contemporary capitalism and urban economic development are discussed at the scale of a transnationally extended urban system. Based on the general context of the global economic downturn, I focus on the role of cities in distinct circuits of capital, the switching of capital flows within the urban system and the different functional roles of cities within the world city network that interconnects cities both in the global North and South. I call into question the established focus of urban economic research on the role of cities as financial and service centres, arguing that cities might redirect their economic development trajectories towards ‘real economy’ activities, in contrast to relying on the disastrous development model of finance‐dominated capitalism.     

Fiscal centralization versus decentralization: Growth and welfare effects of spillovers, Leviathan taxation, and capital mobility

This paper develops an endogenous growth model with spillovers of public goods, Leviathan taxation, and mobile capital to examine the relative merits of centralized and decentralized fiscal systems for economic growth and social welfare. We show that a decentralized system dominates a centralized system in terms of economic growth; however, the difference in social welfare between a decentralized and a centralized system is non-monotonic and displays a hump-shaped relationship with respect to capital mobility. Since higher capital mobility induces stronger tax competition, this finding implies that there is an optimal degree of tax competition; some tax competition is desirable, but fierce tax competition may be harmful. We also show that there is a critical level of spillovers of public goods above which centralization dominates decentralization in terms of social welfare, as in previous studies; however, if spillovers are below this critical level, capital mobility also matters in the welfare comparison between centralized and decentralized systems.     

Effects of foreign aid on the recipient country’s economic growth

We introduce an infinite-horizon endogenous growth framework for studying the effects of foreign aid on the economic growth in a recipient country. Aid is used to partially finance the recipient’s public investment. We point out that the same rule of aid may have very different outcomes, depending on the recipient’s circumstances in terms of development level, domestic investment, efficiency in the use of aid and in public investment, etc. Foreign aid may promote growth in the recipient country, but the global dynamics of equilibrium are complex (because of the non-monotonicity and steady state multiplicity). The economy may converge to a steady state or grow without bounds. Moreover, there are rooms for the divergence and a two-period cycle. We characterize conditions under which each scenario takes place. Our analysis contributes to the debate on the nexus between aid and economic growth and in particular on the conditionality of aid effects.     

Product differentiation,monopolistic competition and city size

Traditionally, the formation of cities has been explained by such supply-side phenomena as scale economies in production or such demand-side phenomena as public goods. This paper presents an integrated demand and supply approach to the formation of cities in spatial economy. Demand considerations, in the form of consumer agglomeration economies (i.e., product variety), are presented as a major cause of urban agglomeration. On the supply side, scale economies are introduced. Both aspects are examined by using the Dixit-Stiglitz model of monopolistic competition to characterize the equilibrium and optimum city size. We also discuss a subsidy scheme that produces an equilibrium city size corresponding to a first-best optimum. Then we analyze the distribution of population in a system of two cities.     

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.     

Consumption paths under prospect utility in an optimal growth model

This paper studies the Cass-Koopmans-Ramsey model of optimal economic growth in the presence of loss aversion and habit formation. The representative agent's preferences for consumption can be gradually varied between the standard constant intertemporal elasticity of substitution (CIES) case and Kahneman and Tversky's prospect utility. We find that the transitional dynamics of optimal consumption paths differ distinctly from the standard model, in particular consumption smoothing is more pronounced. We also show that prospect utility can cause the economy to remain in a steady state with low consumption and low capital.     

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.     

Indeterminacy in a finance constrained unionized economy

We introduce labor unions and unemployment in a finance constrained monetary economy with heterogenous agents and productive labor externalities. We find that unions, introducing endogenous markup variability, influence the dynamics of the model. Although a lower bound for labor externalities is always required for indeterminacy, this lower bound decreases with union power when the elasticity of substitution between capital and labor is above one. For values of this elasticity below one, this result is reversed. We also show that Hopf bifurcations may occur as union bargaining power crosses a critical value. Finally, we find that unions increase simultaneously steady state employment, capital accumulation and welfare iff the (equilibrium) marginal productivity of labor is decreasing in employment.     

公共资本生产率的比较研究——基于长三角21城市公共资本边际生产率的实证分析

近10年来长三角的政府公共投资（分配）过多地流向了上海、苏州、杭州、南京等核心城市，使这些城市的人均公共资本拥有量大幅上升，从而引发了其边际生产率递减情况的发生。但它们的资本利用效率或技术创新水平没有明显提升（或下降），不足以抵消其资本边际生产率下降的趋势。对这些大城市的经济发展来说，公共投资对其经济增长的意义已经在数量上表现得不明显，但对正处于经济快速增长期且资本边际生产率呈递增态势的长三角外缘中小城市而言，公共投资却有着积极意义。     

Ramsey equilibrium with liberal borrowing

This paper considers a multi-agent one-sector Ramsey equilibrium growth model with borrowing constraints. The extreme borrowing constraint used in the classical version of the model, surveyed in Becker (2006), and the limited form of borrowing constraint examined in Borissov and Dubey (2015) are relaxed to allow more liberal borrowing by the households. A perfect foresight equilibrium is shown to exist in this economy. We describe the steady state equilibria for the liberal borrowing regime and show that as the borrowing regime is progressively liberalized, the steady state wealth inequality increases. Unlike the case of a limited borrowing regime, an equilibrium path need not converge in the case of liberal borrowing regime. We show through an example that a two period cyclic equilibrium exists when agents are allowed to borrow against their two period future wage income. This result is similar to the possibility of non-convergent equilibrium capital stock sequences in the model with no borrowing.     

WHAT HAS HAPPENED TO THE CYCLE?

The Chancellor reminded us in his Budget speech that "the British economy is now embarking on its seventh successive year of steady growth, at an average rate of getting on for 3 per cent a year". This experience contrasts markedly with that of the 1970s and is dissimilar from that of the 1960s. Here we examine the recent behaviour of the economy, particularly with regard to the cycle. We conclude that the cycle is not dead and that since the trough of 1981 the economy has passed through two further turning points. If a correction is made for the miners' strike, activity peaked in late 1984, reached a trough in 1985 and is currently once more growing at an above-trend rate.     

Infectious diseases and economic growth

This paper develops a framework to study the economic impact of infectious diseases by integrating epidemiological dynamics into a neo-classical growth model. There is a two way interaction between the economy and the disease: the incidence of the disease affects labor supply, and investment in health capital can affect the incidence and recuperation from the disease. Thus, both the disease incidence and the income levels are endogenous. The disease dynamics make the control problem non-convex thus usual optimal control results do not apply. We establish existence of an optimal solution, continuity of state variables, show directly that the Hamiltonian inequality holds thus establishing optimality of interior paths that satisfy necessary conditions, and of the steady states. There are multiple steady states and the local dynamics of the model are fully characterized. A disease-free steady state always exists, but it could be unstable. A disease-endemic steady state may exist, in which the optimal health expenditure can be positive or zero depending on the parameters of the model. The interaction of the disease and economic variables is non-linear and can be non-monotonic.     

Asset bubbles and borrowing constraints

In this paper, we study the existence of asset bubbles in an overlapping generations economy à la Tirole [Tirole, J., 1985. Asset bubbles and overlapping generations. Econometrica 53, 1499–1528] with borrowing constraints. Deriving a condition for the existence of equilibrium paths with bubbles, we demonstrate that (i) a monetary steady state (a steady state with bubbles) is constrained dynamically inefficient, whereas capital in the monetary steady state is underaccumulating relative to the quasi-golden rule, (ii) there exists a government intervention which corrects the constrained dynamic inefficiency, and (iii) for some parameter values, such a government intervention reduces the utilities of agents with high productivity, while it increases per capita consumption.     

Geographic poverty traps? A micro model of consumption growth in rural China

How important are neighbourhood endowments of physical and human capital in explaining diverging fortunes over time for otherwise identical households in a developing rural economy? To answer this question we develop an estimable micro model of consumption growth allowing for constraints on factor mobility and externalities, whereby geographic capital can influence the productivity of a household's own capital. Our statistical test has considerable power in detecting geographic effects given that we control for latent heterogeneity in measured consumption growth rates at the micro level. We find robust evidence of geographic poverty traps in farm‐household panel data from post‐reform rural China. Our results strengthen the equity and efficiency case for public investment in lagging poor areas in this setting. Copyright © 2002 John Wiley & Sons, Ltd.     

Pollution,mortality and time consistent abatement taxes

We study dynamically consistent policy in a neoclassical overlapping generations growth model where pollution externalities undermine health but are mitigated via tax-financed abatement. With arbitrarily constant taxation, two steady states arise: an unstable ‘poverty trap’ and a ‘neoclassical’ steady state near which the dynamics might either be monotonically convergent or oscillating. When the planner chooses a time consistent abatement path that maximizes a weighted intergenerational sum of expected utility, the optimal tax is zero at low levels of capital and then a weakly increasing function of the capital stock. The non-homogeneity of the tax function along with its feedback effect on savings induces additional steady states, stability reversals and oscillations.     

Social Welfare and Income Inequality in a System of Cities

This paper develops a general-equilibrium model of a system of core-periphery cities to examine the main determinants of intra- and inter-regional income disparities. The economy is populated by a continuum of (homogeneous) unskilled and (heterogeneous) skilled workers. Unskilled workers, whose wages are determined competitively, specialize in food production in local cities; skilled workers, whose wages are determined according to a Nash bargain, manufacture a high-tech commodity in the metropolis. We establish conditions under which this core-periphery equilibrium spatial configuration emerges. We show that both intra- and inter-regional income disparities are present; the determinants of each type of disparity and the social-welfare implications are fully investigated. Our results suggest that public policy programs that improve income equality may not be necessarily welfare enhancing.     

DEBATES AND DEVELOPMENTS. Competitive Cities and Secure Nations: Conflict and Convergence in Urban Waterfront Agendas after 9/11

In this exploratory article we investigate how longstanding ‘competitive city’ projects are actively reshaped by recent national security initiatives in urban waterfronts. We argue that port districts in large waterfront cities are becoming critical sites where actors are struggling to further different agendas. While proponents of competitive city projects appear directly concerned with promoting a particular vision of capitalist urban development in contrast to the national security agenda of port and border securitization, we contend that a simple dichotomy between ‘economy’ and ‘security’ cannot capture their complex intermingling. We examine the emergent public discourses of port (in)security in the US and Canada since 9/11, paying particular attention to the convergences between port security and waterfront gentrification initiatives, while also noting conflicts between these agendas. We identify four key areas of change: relations of power in the governance of port spaces, rationales of urban planning decisions, physical redesign of urban port spaces, and conflicts between ‘economy’ and ‘security’. Post 9/11 port security initiatives are sometimes at odds and other times at ease with the competitive city agendas that are readily apparent in urban waterfront redevelopments. Both projects have disturbing implications for social justice in waterfront cities.