Estimating the gravity model when zero trade flows are frequent and economically determined

ABSTRACT

Since the 1950s, we have known that the presence of zero-valued dependent variables can seriously bias econometric estimates whether the zeros are included or excluded. Yet the widely-used gravity model is frequently estimated on samples that include large fractions of zeros. An influential paper by Santos Silva and Tenreyro – based on simulations that include no economically-determined zeros – concludes that the bias problems resulting from zeros and those resulting from heteroscedasticity and nonlinearity can be solved using the Poisson Pseudo-Maximum-Likelihood (PPML) model including the zero values. This paper begins by adapting the Santos Silva and Tenreyro experimental design to include economically-determined zeros to see whether this conclusion continues to hold. With this design, it finds that alternative estimators have lower bias than PPML. Changing to a Monte Carlo design that replicates the much-higher real-world frequency of predicted values near zero restores the finding of lower bias with the PPML estimator. The results highlight the need for very careful design of Monte Carlo experiments when evaluating alternative estimators of the gravity model.     

The Perverse Effect of Debt Tax Benefits on Firm Investment Decisions

In this paper we question the idea that the deduction of debt interest is always an effective policy instrument to spur firm investment. We analyse the investment decision in presence of a borrowing constraint on the amount of debt that the firm can raise. We show that if the debt interest rate is decreasing in the firm's capital accumulation and another financial resource more expensive than debt is available (at least for levels of debt lower than the upper bound), then the deduction of the debt interest from taxes on capital income may reduce firm investment. This theoretical result is relevant for economic policy decisions when financial intermediaries are not willing to finance beyond a certain threshold but firms have access to other sources of finance.     

个人投资者交易行为研究——来自台湾股市的证据

本文基于台湾股市数据,主要研究个人投资者的交易行为。参照Kaniel et al.(2008)构建了个人投资者交易不平衡性指标─净交易,以反映投资者股票交易的强度。采用这种交易不平衡性指标来构建投资组合研究个人投资者的交易行为。首先研究个人投资者交易和股票的收益之间的动态关系从而分析投资者的交易策略,然后研究个人投资者净交易的收益预测能力从而分析个人投资者交易的信息含量。本文研究发现:台湾股票市场的个人投资者采用负反馈的交易策略,并且个人投资者在交易中表现出很强的处置效应;个人投资者在交易中的信息含量不足;个人投资者交易中的盈利主要来自两个方面:过度反应和价格冲击。文章最后给出政策建议。     

Foreclosure,REO, and Market Sales in Residential Real Estate

Assessment of lender and third-party bidder acquired properties at foreclosure auction is provided. Properties acquired at foreclosure auction by third-party bidders transact at a discount to lender dispositions of real estate owned (REO) properties. The discount reflects a reduction in costs associated with lender owned (REO) dispositions and uncertainty faced by third-party bidders. Moreover, there is a ranking in transaction prices among initial purchases by third-party bidders at foreclosure auction, REO sales, non-distressed property sales and the subsequent sales of third-party bidder acquired properties. Third-party bidder auction prices are below REO sale prices, which are below non-distressed property sale prices, which are below the subsequent sale prices of third-party bidder acquired properties. The price spacing by cohort is logical, intuitive and economically justified in a market with rational participants. Implications are also apparent for the measurement of price changes, net sale proceeds and returns to residential real estate.     

Efficiency and Technological Change in the U.S. Brewing Industry

This study demonstrates that the measurement of technological change and economic efficiency are tightly linked. Efficiency measures may depend on carefully controlling for technological change, while tests of technological change may be sensitive to empirical model specifications. Moreover, the study underlines Solow's (1994) and Romer's (1994) admonition that econometricians should pay attention to industry and institutional evidence in building models of technological change. The empirical results presented here suggest that there has been substantial technological change in the U.S. brewing industry from 1950 to 1992. This occurred in the form of a dramatic shift in technology beginning with the introduction of super breweries in about 1972. There has also been a substantial increase in scale economies, which undoubtedly caused many inefficiently small firms to exit the industry during the 1960s and 1970s. Further results suggest that a more complete specification of technological change and the stochastic nature of the frontier production function leads to higher and more tenable estimates of efficiency.     

Business cycle amplification with heterogeneous expectations

This paper studies the implications for business cycle dynamics of heterogeneous expectations in a stochastic growth model. The assumption of homogeneous, rational expectations is replaced with a heterogeneous expectations model where a fraction of agents hold rational expectations and the remaining fraction adopt parsimonious forecasting models that are, in equilibrium, optimal within a restricted class. Our approach nests the literature on rational expectations in business cycle models with a recent approach based on adaptive learning. We demonstrate that (i.) heterogeneous expectations can lead to substantial improvement in the internal propagation of equilibrium business cycle models and (ii.) the internal propagation depends on the degree of heterogeneity. A calibrated model with heterogeneity provides a closer fit to business cycle data than its representative agent, rational expectations counterpart.     

PRODUCT AND LABOUR MARKETS IN WAGE DETERMINATION: SOME AUSTRALIAN EVIDENCE

The study is concerned with the extent to which workplace wage drift is influenced by establishment-specific or occupation-specific factors. It demonstrates, by analysis of variance of pay data from a survey of 44 occupations in 198 workplaces, that the sources of variation are predominantly establishment-specific. There is evidence of a link between the amount of discretion an employer exercises in the labour market and the degree of concentration in his product market. It is argued that discussions of pay determination have been unduly preoccupied with labour market processes and have neglected the variation in employer behaviour arising from differences in product market.