Optimal harvesting of a spatial renewable resource

In this paper we investigate the optimal harvesting of a renewable natural resource. While in most standard approaches the resource is located at a single point, we allow the resource to be distributed spatially. Consequently, an agent who exploits the resource has to travel from one location to another. For a fixed planning horizon, we investigate the speed and the path of harvesting chosen by the agent. We show that the agent adjusts this speed so as to visit each location only once, even in the absence of travelling cost. Since the agent does not return to any location for a second harvest, it is optimal to fully deplete the resource upon arrival. A similar type of bang–bang solution results when we drop the assumption of a constant harvesting rate: allowing for a variable harvesting rate, the agent chooses to fully exploit the resource either in the last or in the first travelling period. A society interested in conserving some of the resource thus has to take measures to limit the exploitative behaviour of the agent.     

Compliance of land cover changes with municipal land use planning: Evidence from the Lisbon metropolitan region (1990–2007)

In the past few decades, urbanisation has become a major phenomenon in European cities, thus representing one of the key human land cover changes with socio-economic and environmental impacts. In the Lisbon metropolitan region it is estimated that 17% of natural and farmland have been transformed into artificial areas. Since the end of 1990s, specific EU guidelines have been issued to contain urban sprawl and preserve agricultural land. Spatial planning in Portugal obviously is integrating these assumptions into the statutory land-use master plans. But what is the performance of this land use planning system regarding land cover evolution itself? Based on the Lisbon metropolitan region (LMR), one of the major areas of urban growth in Portugal, we examine spatio-temporal land cover patterns between 1990 and 2007 by integrating cross-matrix analysis, spatial metrics, and gradient analysis. Additionally, we overlay these land cover dynamics with municipal master plans that regulate land development in order to assess the compliance levels of this land-use regulatory system. Results indicate that: artificial areas are growing by coalescence and/or by scattered development along an urban–rural gradient; agricultural land is reducing and fragmentation is increasing to enlarge peri-urban spaces; there are high levels of conversion of agricultural land into urban land in protected areas, thus showing a lack of compliance to the land use regulatory system visible in the existing gaps between the original land-use assignments of the master plan and the actual developments.     

The willingness to pay–willingness to accept gap: A failed replication of Plott and Zeiler

The well-known willingness to pay–willingness to accept (WTP–WTA) gap refers to the observation that individuals attach a higher value to objects they own (WTA) than to objects they do not own (WTP). We report on experiments to re-investigate the possibility that the WTP–WTA gap arises from subject misconceptions due to experimental procedures as suggested by Plott and Zeiler (2005). The contribution of this paper is two-fold: first, we attempt to replicate the findings by Plott and Zeiler that the WTP–WTA gap disappears when using procedures that are aimed at reducing misconceptions, such as extensive training and practice rounds for the BDM mechanism. However, we fail to do so as the WTP–WTA gap persists in the main task where subjects state their WTA or WTP for a mug. Second, we use the paid practice rounds to identify subjects without apparent misconceptions and find that also for those subjects who never make dominated choices in the lottery tasks, the WTP–WTA gap in the mug task exists. Thus, we find no evidence of the idea that subject misconceptions are the main source of the WTP–WTA gap.     

The consumption–investment decision of a prospect theory household: A two-period model

This study extends the literature on portfolio choice under prospect theory preferences by introducing a two-period life cycle model, where the sufficiently loss averse household decides on optimal consumption and investment in a portfolio with one risk-free and one risky asset. The optimal solution depends primarily on whether the household’s present value of the consumption reference levels is below, equal to, or above the present value of its endowment income. Reference levels below the endowment income are associated with the self-enhancement motive. In this case, the household avoids relative losses in consumption in any present or future state of nature (good or bad). As a result the degree of loss aversion does not directly affect optimal consumption and risk taking activity. Reference levels equal to the endowment income are associated with the belonging motive. An example would be a household comparing to others that belong to the same social class. In this case the household’s optimal consumption is the reference consumption and the household will not invest in the risky asset. Finally, reference levels above the endowment income are associated with the self-improvement motive (or high aspirations). For such high reference levels, households cannot avoid experiencing a relative loss in consumption, either now or in the future. As a result, loss aversion directly affects consumption and risky investment.     

Sources of business fluctuations: Financial or technology shocks?

Despite the widespread belief that technology shocks are the main source of business fluctuations, recent empirical studies indicate that in the absence of financial frictions, a shock to the marginal efficiency of investment is the main source and is closely related to financial conditions for investment. We incorporate a financial accelerator mechanism and two types of financial shocks to the external finance premium and net worth in a dynamic stochastic general equilibrium model with shocks to the marginal efficiency of investment, the investment-good price markup, and the rates of neutral and investment-specific technological changes. This model is estimated using eleven US time series that include data on loan, net worth, the loan rate, and the relative price of investment. Our estimation results show that the (non-stationary) neutral and investment-specific technology shocks primarily drive output and investment fluctuations, while the external finance premium shock plays an important role for investment fluctuations. This financial shock induced substantial falls and subsequent sharp hikes in the external finance premium and caused boom–bust cycles over the past two decades.     

Beyond Asymmetry: Substantive Beliefs in Preference Formation and Efficiency of Asymmetrical Negotiations

Contrary to extant propositions on the primacy of trade dependency in compelling faster agreement by subordinate states in asymmetrical economic negotiations, in the European Union–Africa, Caribbean and Pacific (EU–ACP) Economic Partnership Agreement (EPA) negotiations, it is the states that were least materially vulnerable that were quickest to accept an EPA. Why so? I argue that the speed and propensity of ACP states to accept and ratify their EPAs were principally hinged on variances in preference formation based on what Ikenberry and Kupchan [(1990), ‘Socialization and Hegemonic Power’, International Organization, 44 (3), pp. 283–315: 283] call ‘substantive beliefs rather than material payoffs’. The quickest states to ratify an EPA were those which most intensely shared the EU's neoliberal belief in an automatic correlation between trade liberalisation and economic growth, rather than those that were most materially vulnerable. Therefore, by taking the normative sources of preference formation by subordinate states seriously, we can not only derive a parsimonious explanation of EPA negotiating efficiency but also form a foundational conceptual model of predicting efficiency in asymmetrical negotiations that unifies the role of both normative and material considerations.     

Why do commercial banks hold government bonds? The case of Japan

We investigate the determinants of the demand for Japanese government bonds (JGBs) by commercial banks in Japan. In particular, by estimating portfolio equations for JGB demand and bank loans, based on a panel data set from the late 1990s to the 2000s, we rigorously test the popular assertion that the long stagnation of the real economy caused a shift in the portfolios of commercial banks from bank lending to JGBs. We find that the popular assertion is not empirically supported. Rather, the portfolio shift from loans to JGBs has been caused by a fall in the ratio of the loan rate to unit lending costs, or the bank’s price–cost margin for lending.     

The efficiency of small and medium enterprises in informal metal manufacturing in Zimbabwe: Implications for stakeholders in the agricultural sector

This study uses the structure–conduct–performance framework to examine the structure and efficiency of small and medium enterprises in the informal metal manufacturing sector in Zimbabwe. Small and medium enterprises provide a lifeline to the country's resource-poor farmers, whose numbers increased exponentially after the agrarian reform in 2000. The study utilises nationally representative, enterprise-level data from five major towns (Harare, Chitungwiza, Bulawayo, Mutare and Rusape) in Zimbabwe. Various performance measures are applied at the industry level to assess efficiency, profitability and competitiveness; these include the Herfindahl–Hirschman index, concentration ratios, average yearly profits and Tobin's q ratio. The results indicate that small and medium enterprises in Zimbabwe are modestly efficient, profitable and competitive. These findings highlight the need to integrate informal metal fabrication activities into Zimbabwe's national economic development plans.     

Truthful germs are contagious: A local-to-global characterization of truthfulness

We study the question of which social choice functions from an abstract type space to a set of outcomes are truthful, i.e., implementable by truthful mechanisms, when utilities are quasi-linear. For convex domains, our main theorem characterizes truthful social choice functions as those satisfying two properties: local weak monotonicity and vortex-freeness. The first of these constrains the function values at any two sufficiently proximal points, while the second asserts that its line integrals around sufficiently small triangular loops must vanish.The characterization implies a local-to-global principle that allows one to deduce truthfulness of a function from its behavior on arbitrarily small neighborhoods of each point. Other consequences include a simple alternate derivation of the Saks–Yu Theorem that weak monotonicity characterizes truthfulness of functions having a convex domain and finite range, and a sufficient condition for constructing truthful functions by “stitching together” truthful subfunctions on different subsets of the domain.     

Firm heterogeneity and immigrant wage assimilation

This article investigates the role of job mobility in immigrant wage assimilation. I use longitudinal linked employer–employee data for Portugal to estimate the immigrant wage catch-up in log wage regressions with both individual and firm fixed effects. I show that moving to firms with higher wage premiums accounts for approximately 30% of the immigrant wage catch-up in the first years.