Invertebrate response to impacts of water diversion and flow regulation in high‐altitude tropical streams

Water supply systems are critical infrastructure that provides food and energy security for developed societies. The operation of reservoirs (flow regulation) and water intakes (water diversion) has known negative impacts on aquatic ecosystems; however, quantification of ecological impacts and examination of these two types of flow alteration remain a developing area of research. We investigated the individual and combined impact of flow regulation and water diversion on stream ecosystem integrity, the freshwater macroinvertebrate community, and the population structure of flow‐sensitive insects. For 2 years, we monitored quarterly discharge, physical and chemical stream conditions, and benthic invertebrates of four high‐altitude tropical streams that are part of the water supply system of Quito, Ecuador. Flow regulation caused a loss of the hydrological seasonality of these streams, including a decrease in stream depth and biotic quality. Water diversion caused a decrease in dissolved oxygen and overall ecosystem integrity. Freshwater invertebrate density and richness decreased as a result of water diversion and flow regulation. The combined flow alteration in these streams decreased the density of nymphal stages of the widely distributed mayfly Andesiops peruvianus. Given the societal needs for food and energy security, water management for diversion (e.g., irrigation) and in‐line storage practices (e.g., hydroelectric dams) are anticipated to increase. This research suggests that the negative environmental impacts of flow alteration could be mitigated with discharge releases designed to approximate the natural hydrologic regime of undisturbed streams.     

On some criteria for the formulation and testing of economic growth models

This paper presents a methodology for the formulation and testing of economic growth models. The model selected includes two production sectors with physical and human capital accumulation. These capital stocks are associated with spillover effects in the production of the physical good and in the accumulation of both factors.     

Endogenous lifetime and economic growth

Endogenous mortality is introduced in a two-period overlapping generations model: probability of surviving from the first period to the next depends upon health capital that is augmented through public investment. High mortality societies do not grow fast since shorter lifespans discourage savings; development traps are possible. Productivity differences across nations result in persistent differences in capital-output ratios and relatively larger gaps in income and mortality. High mortality also reduces returns on education, where risks are undiversifiable. When human capital drives economic growth, countries differing in health capital do not converge to similar living standards, ‘threshold effects’ may also result.     

Why are some people (and countries) more protectionist than others?

We analyze two cross-country data sets that contain information on attitudes toward trade as well as a broad range of socio-demographic and other indicators. We find that pro-trade preferences are significantly and robustly correlated with an individual's level of human capital, in the manner predicted by the factor endowments model. Preferences over trade are also correlated with the trade exposure of the sector in which an individual is employed: individuals in non-traded sectors tend to be the most pro-trade, while individuals in sectors with a revealed comparative disadvantage are the most protectionist. Third, an individual's relative economic status has a very strong positive association with pro-trade attitudes. Finally, non-economic determinants, in the form of values, identities, and attachments, play an important role in explaining the variation in preferences over trade. High degrees of neighborhood attachment and nationalism/patriotism are associated with protectionist tendencies.     

Tax competition and tax structure in open federal economies: Evidence from OECD countries with implications for the European Union

Tax competition arguments suggest that governments that operate in an open economy (such as local governments) should not and will not rely on non-benefit taxes, such as the income tax. Yet we observe reliance on income taxes by local governments in many countries, and such reliance changes over time. Evidence from a panel data set of 13 OECD countries over the period 1975-1984 suggests that competition between levels of government (resulting in a vertical fiscal externality) and between governments at the same level (resulting in a horizontal fiscal externality) provide some economic rationale for these changes. Moreover, the evidence indicates that the vertical and horizontal fiscal externalities interact. These results have some interesting implications for fiscal policy in the European Union, particularly as the EU continues to evolve. One implication for the EU is that enlargement that increases tax base disparities within the EU (and is not accompanied by an EU-level income tax) will tend to lower national income tax rates, although this must be qualified because it also depends on the mobility of the population. A second implication is that fiscal expansion of the EU to include an EU-level income tax may tend to lower the reliance of national governments on income taxes through the vertical externality, but may also tend to equalize tax bases across countries, and so increase reliance on national income taxes through the horizontal externality.     

On exact D-optimal designs with 2 two-level factors and n autocorrelated observations

In this paper we consider the exact D-optimal designs for estimation of the unknown parameters in the two factors, each at only two-level, main effects model with autocorrelated errors. The vector of the n random errors in the observed responses is assumed to follow a first-order autoregressive model (AR(1)). The exact D-optimal designs seek the optimal combinations of the design levels as well as the optimal run orders, so that the determinant of the information matrix of BLUEs for the unknown parameters is maximized. Bora-Senta and Moyssiadis (1999) gave some conjectures about the exact D-optimal designs based on their experience of several exhaustive searches. In this paper their conjectures are partially proved to be true.Received: January 2003 / Accepted: October 2003Partially supported by the National Science Council of Taiwan, R.O.C. under grant NSC 91-2115-M-008-013.Supported in part by the National Science Council of Taiwan, R.O.C. under grant NSC 89-2118-M-110-003.     

Overnight borrowing, interest rates and extreme value theory

We examine the dynamics of extreme values of overnight borrowing rates in an inter-bank money market before a financial crisis during which overnight borrowing rates rocketed up to (simple annual) 4000 percent. It is shown that the generalized Pareto distribution fits well to the extreme values of the interest rate distribution. We also provide predictions of extreme overnight borrowing rates using pre-crisis data. The examination of tails (extreme values) provides answers to such issues as to what are the extreme movements to be expected in financial markets; is there a possibility for even larger movements and, are there theoretical processes that can model the type of fat-tails in the observed data? The answers to such questions are essential for proper management of financial exposures and laying ground for regulations.     

Assessing French nursing home efficiency: An indirect approach via budget-constrained DEA models

In this paper, data envelopment analysis (DEA) techniques are applied to the French nursing home industry in order to address two policy issues. The first involves nursing home size and returns to scale, while the second deals with the potential effects of a change in nursing home reimbursement from a flat rate to one based on the severity of case-mix. To accomplish this, our analysis expands on the existing nursing home literature to analyze technical and allocative efficiency along with budget-constrained models rather than the more common direct input-based distance function. Technical efficiency is evaluated via an indirect output distance function while allocative output efficiency is computed with a cost indirect revenue function. The findings suggest that system-wide efficiency and equity may result from coming reforms since payments would more accurately reflect resource use.     

Less Government—More Wealth? On the Macroeconomics of a Smaller Public Sector in Europe

In this paper, we analyze the reactions of European economies to a fiscal policy strategy aiming at diminishing the public sector. Within the framework of the MSG3 model, a macroeconomic model of the world economy, we perform several simulation experiments to explore the effects of reducing government expenditures permanently in different phases of the business cycle. For this purpose, we combine the fiscal contraction with negative and positive, Euro Area-wide and global, supply and demand shocks. It turns out that adverse Keynesian effects on output and employment tend to be mostly weak and short-lived, whereas long-run effects on output and employment are favorable. Due to these long-run effects, the fiscal contraction policy raises welfare as measured by an asymmetric quadratic objective function. The size of these welfare effects depends on the initial situation in a non-trivial manner.     

The structural transformation and aggregate productivity in Portugal

We document the substantial process of structural transformation—the reallocation of labor between agriculture, manufacturing, and services—and aggregate productivity growth undergone by Portugal between 1956 and 1995. We assess the quantitative role of sectoral labor productivity in accounting for these processes. We calibrate a model of the structural transformation to data for the United States and use the model to gain insight into the factors driving the structural transformation and aggregate productivity growth in Portugal. The model implies that Portugal features low and roughly constant relative productivity in agriculture and services (around 22%) and a modest but growing relative productivity in manufacturing (from 44 to 110%). We find that productivity growth in manufacturing accounts for most of the reduction of the aggregate productivity gap with the United States and that a further closing of this gap can only be accomplished via improvements in the relative productivity of services. This paper was written while the authors were affiliated with the Federal Reserve Bank of Richmond. We would like to thank the editor, two anonymous referees, and participants at the Third Conference on Portuguese Economic Development in the European Context organized by the Bank of Portugal for their comments. All errors are our own.