Stability of stochastic optimal growth models: a new approach

The paper proposes an Euler equation technique for analyzing the stability of differentiable stochastic programs. The main innovation is to use marginal reward directly as a Foster-Lyapunov function. This allows us to extend known stability results for stochastic optimal growth models, both weakening hypotheses and strengthening conclusions.     

Irreversible investment and Knightian uncertainty

When firms make a decision about irreversible investment, they may not have complete confidence about their perceived probability measure describing future uncertainty. They may think other probability measures perturbed from the original one are also possible. Such uncertainty, characterized by not a single probability measure but a set of probability measures, is called “Knightian uncertainty.” The effect of Knightian uncertainty on the value of irreversible investment opportunity is shown to be drastically different from that of traditional uncertainty in the form of risk. Specifically, an increase in Knightian uncertainty decreases the value of investment opportunity while an increase in risk increases it.     

Comments’ Extraction by User ID,Keywords, and Anchor Texts from the Thread of a Bulletin Board System

Bulletin Board Systems (BBSs) on the Web are used by many users posting comments on threads. Each thread carries a subject of discussion. Most users post comments related to a subject. However, unrelated comments are also posted. The unrelated comments distract users and diminish their understanding of the entire story of a thread. Comments unrelated to a subject have to be filtered automatically. This paper proposes a method that extracts comments related to a thread subject from a thread of BBS. The method extracts two types of comments: comments related to a thread subject (main comments), and comments related to main comments (sub-comments). The main comments are extracted by a user ID and keywords in the comments. The sub-comments are extracted by explicit and implicit anchor texts in the comments. We experimented with the proposed method and verified that comments extracted by the proposed method support participants in understanding the entire story of a thread.     

Welfare gain from quality and price development in the Japan’s LCD TV market

We estimate the welfare gain from innovations in the LCD TVs that prevailed during the period 2005–2007 in Japan, via consumer surplus that we measure with the aid of discrete choice methods, using market data obtained from an internet price comparison service (Kakaku.com). Further, by the measured implicit values of attributes, we evaluate in monetary terms, the qualitative transition embedded in the attributes through the iso-consumer surplus planes. We thereby disaggregate the welfare gain into the qualitative and the budgetary components, which we call the quality gain, and the budget gain, respectively. The estimates show, along with the evolved process of innovation, that the quality gain was in the order of 381 KJPY, while the budget gain was 94 KJPY negative, which gives about 287 KJPY of overall welfare gain per consumer, during the period.     

A dynamic two country Heckscher–Ohlin model with non-homothetic preferences

We examine the properties of a two-country dynamic Heckscher–Ohlin model that allows for preferences to be non-homothetic. We show that the model has a continuum of steady state equilibria under free trade, with the initial conditions determining which equilibrium will be attained. We establish conditions under which a static Heckscher–Ohlin theorem will hold in the steady state, and also conditions for a dynamic Heckscher–Ohlin theorem to hold. If both goods are normal, each country will have a unique autarkic steady state, and all steady state equilibria are saddle points. We also consider the case in which one good is inferior, and show that this can lead to multiple autarkic steady states, violations of the static Heckscher–Ohlin theorem in the steady state. Furthermore, there may exist steady state equilibria that Pareto dominate other steady states. These steady states will be unstable if discount factors are the same in each country, although they may exhibit dynamic indeterminacy if discount factors differ.     

Residential rents and price rigidity: Micro structure and macro consequences

Why was the Japanese consumer price index for rents so stable even during the period of the housing bubble in the 1980s? To address this question, we use a unique micro price dataset which we have compiled from individual listings (or transactions) in a widely circulated real estate advertisement magazine. This dataset contains more than 700,000 listings of housing rents over the last 20 years. We start from the analysis of microeconomic rigidity and then investigate its implications for aggregate price dynamics, closely following the empirical strategy proposed by Caballero (Caballero and Engel, 2007). We find that 90% of the units in our dataset had no change in rents per year, indicating that rent stickiness is three times as high as in the United States. We also find that the probability of rent adjustment depends little on the deviation of the actual rent from its target level, suggesting that rent adjustments are not state-dependent but time-dependent. These two results indicate that both the intensive and extensive margins of rent adjustments are small, resulting in a slow response of the CPI for rent to aggregate shocks. We show that the CPI inflation rate would have been higher by 1% point during the bubble period, and lower by more than 1% point during the period following the burst of the bubble, if Japanese housing rents were as flexible as those in the United States.     

Expectation-driven fluctuations and welfare loss under free trade in two-country models

This paper investigates the interlinkage in the business cycles based on expectation-driven fluctuations of large-country economies in a free-trade equilibrium. We consider a two-country, two-good, two-factor general equilibrium model with sector-specific externalities. We show that some country's expectation-driven fluctuations can spread throughout the world once trade opens even if the other country has determinacy under autarky. We thus prove that under free trade, globalization and market integration can have destabilizing effects on a country's competitive equilibrium. Finally, we characterize a configuration in which opening to international trade improves the stationary welfare at the world level but deteriorates the stationary welfare of the country that imports investment goods and exports consumption goods. We conclude that in opposition to the standard belief, international trade might not be beneficial to all trading partners in the long run.     

On the shape of the single-country and world commodity-substitution and factor-substitution surfaces under conditions of joint production

In recent years trade theorists have completed the task of specifying necessary and sufficient conditions for the single-country and world transformation surfaces to be locally of any assigned degree of flatness. However those conditions are relevant only if the technology is of the no-joint-products type. In the present note we derive necessary and sufficient conditions for the single-country and world transformation surfaces to be of any assigned degree of flatness under conditions of joint production; and we also obtain, as a by-product, necessary and sufficient conditions for the single-country and world equal-product surfaces to be of any assigned degree of flatness.     

Economic Development in Asian Countries, and the Effectof Trade in Asia on Employment and Wages in Japan

There is a controversy in the USA and several European countries on whether or not an increase in imports in manufacturing goods from low-wage developing countries has major effects on employment and wages in industrialized countries. This paper examines the issue for Japanese imports, paying a particular attention to the effect of manufacturing imports from Asian countries on employment and wages in Japan. It is found that the effect has not been large to date, but that there could be negative effects on employment and, in particular, wages if imports from China and India were to increase substantially.     

THE ROLE AND INTERNALIZATION OF HOMOGENEOUS AND NON‐HOMOGENEOUS DESIGN EFFECTS IN RECYCLING SYSTEMS

This paper considers recycling systems in which producers and a monopolistic recycler are independent agents, while the design of products determined by the producer affects the recycler's productivity. It is found that such design effects could be internalized within the economy, if the monopolistic recycler pays the normative values of the wasted products according to their designs, while the producers formulate design so as to minimize the product's net price. However, if unfortunate, the equilibrium may fall into a local optimum and may not be stable. We also investigate how such property of the equilibrium could be changed if the recycler's productivity is influenced by the diversity in recycle design.