Cities under stress

This paper studies the effect of terrorist attacks on the internal structure of cities. We develop an urban framework with capital structures suitable for the study of this question and analyze the long and short term implications of this type of events. In the long run, the analysis shows that a terrorist attack will affect urban structure only modestly, relative to the potentially large decrease in the level of economic activity in the city. Land rents will not decline at all locations. In the short run, agglomeration forces will amplify the effect of the original destruction and will reduce urban economic activity temporarily.     

Entry and growth in a perfectly competitive vintage model

A perfectly competitive vintage-knowledge model of Schumpeterian growth is introduced to study the relation between growth, technology-lifetime, entry, and productivity-dispersion. The incentive to innovate is generated by the productivity-dispersion (latent in traditional vintage models) between new and old plants, rather than by monopoly rents. The model has a unique steady-state REE with endogenous growth. The endogenous extent of entry constitutes a buffer, dampening the effect of research-efficiency and completely neutralizing the effect of population size or population growth rates on per-capita income levels and growth rates. Variations of research-efficiency lead to a negative relation between growth and vintage-lifetime and a non-monotonic relation between growth and productivity-dispersion.     

LIQUIDITY AND THE INFORMATIONAL EFFICIENCY OF AFRICAN STOCK MARKETS

The hypothesis that a stock market price index follows a random walk is tested for 11 African stock markets, Botswana, Côte d'Ivoire, Egypt, Ghana, Kenya, Mauritius, Morocco, Nigeria, South Africa, Tunisia and Zimbabwe using joint variance ratio tests with finite-sample critical values, over the period beginning in January 2000 and ending in September 2006. The iid random walk hypothesis is rejected in all 11 markets. In four stock markets, Egypt, Nigeria, Tunisia and South Africa, weekly returns are a martingale difference sequence. Liquidity is an important factor which contributes to whether a stock market follows a random walk.     

Technological innovation and real investment booms and busts

We investigate why new, high-risk technologies can attract excessive and often unprofitable investment. We develop an equilibrium model in which rational, risk-averse agents overinvest in a risky technology, possibly to the point that its expected return is negative. Overinvestment results from relative wealth concerns which arise endogenously from the imperfect tradability of future endowments. Competition over future consumption leads to an indirect utility for wealth with “keeping up with the Joneses” properties that can induce herding. Because overinvestment increases with the risk of the technology, our model can explain why new, risky technological innovations may promote investment bubbles.     

Equity‐Based Compensation for Employees: Firm Performance and Determinants

I examine the effect of employee equity‐based compensation (EBC) on firm performance and the determinants of EBC. Using two samples, I find that firms have come to rely more heavily on EBC than in the past. For both samples, I document a significant, positive relation between Tobin's q and the percentage of employee compensation that is equity based. For accounting returns, I find a positive relation with the earlier sample. However, for the later sample I find that greater use of EBC leads to lower levels of future accounting returns. I also find that the determinants of the proportion of EBC are different between the two samples.     

Demographic and Economic Pressure on Emigration out of Africa*

Two of the main forces driving European emigration in the late nineteenth century were real wage gaps between sending and receiving regions and demographic booms in the low‐wage sending regions. Our new estimates of net migration for the countries of sub‐Saharan Africa show that exactly the same forces driving African across‐border migration are at work today. The results suggest that rapid growth in the cohort of potential young emigrants, population pressure on the resource base, and slow economic growth are likely to intensify the pressure for migration out of Africa and into high‐wage OECD countries over the next two decades.     

Productivity growth in Indian agriculture: is there evidence of convergence across states?

This paper explores the question of convergence in total factor productivity (TFP) in agriculture across fourteen major agricultural states of India. Using a Törnqvist–Theil index for TFP growth for the period 1973–1993, we find no evidence to support convergence to a single TFP level (σ‐convergence). After grouping the various states on the basis of their productivity performance, we find that the high‐performing states show a gradual movement towards the trend, whereas the low‐performing states generally show more volatility. Testing for long‐run convergence in levels of agricultural productivity, we find evidence of conditional beta‐convergence after controlling for state‐specific factors and idiosyncratic year‐specific volatility. The results are robust to alternative specifications of tests of unit root in panel data developed recently.     

Fiscal Decentralisation and Economic Growth in High‐Income OECD Countries

Among the majority of high–income OECD countries, the degree of fiscal decentralisation has converged over the last 30 years towards an intermediate level. The theoretical arguments for and against fiscal decentralisation point to explanations for this tendency, because both extreme decentralisation and extreme centralisation are associated with disadvantages for economic growth. Hence, the observed trend of convergence would be growth–promoting. The paper analyses the long–run empirical relationship between per capita economic growth, capital formation and total factor productivity growth, and fiscal decentralisation for the high–income OECD countries. The evidence supports the view that the relationship is positive when fiscal decentralisation is increasing from low levels, but then reaches a peak and turns negative. A policy implication is that policy–makers in several countries with relatively low degrees of fiscal decentralisation could possibly mobilise growth reserves by increasing it.     

Moore's Law and the Semiconductor Industry: A Vintage Model*

In this paper we develop a vintage model to gain a better understanding of the semiconductor industry and its role in recent U.S. productivity gains. Unlike previous work, in our model the observed price declines of individual chips are driven by the introduction of better vintages rather than by learning economies. Dominated chips, nonetheless, continue to be produced, for a time, due to sunk investments in chip‐specific production equipment. The model lends partial support to Jorgenson's hypothesis that an exogenous increase in Moore's Law could have generated the more rapid price declines, and faster productivity growth, seen after 1995.     

Markets and pro-poor agricultural growth: insights from livelihood and informal rural economy models in Malawi

This article presents the development of a set of programming models describing the major features of different rural livelihoods and of the informal rural economy they together make up in Malawi. The models allow for differentiated responses by different household types to change and for the partial equilibrium effects of consequent supply, demand, and price adjustments in labor and grain markets. The models provide insights into the relations between own‐farm and nonown‐farm activities in different households' livelihoods and in the informal rural economy as a whole, and are used to investigate possible impacts of increasing cash crop prices and of a more open rural economy. Impacts of these changes on the poor are found to be critically dependent upon supply and demand elasticities in labor and grain markets, but the poor could potentially suffer significant losses from increased openness of the local economy leading to increased expenditure by less poor households on imported goods and services.