The increasing returns to scale CES production function and the law of diminishing marginal returns

This article analyzes the constant elasticity of substitution (CES) production function when there are increasing returns to scale and the elasticity of substitution exceeds 1, which I refer to as the explosive case of the CES. For this explosive case of the CES, the article demonstrates a new and surprising result: marginal and average products of labor and capital approach infinity as either labor or capital approach infinity. Obviously, in this explosive case of the CES, the law of diminishing marginal returns is eventually violated in a dramatic way. Some implications of this result for growth theory are discussed. The article concludes by deriving, for this explosive case of the CES, lower and upper bounds for the capital labor ratio which are consistent with the law of diminishing marginal returns.     

Returns to school resources in the Jim Crow South

We estimate returns to school resources in the Jim Crow era, as measured by young males' 1940 wage earnings, occupational status, and cognitive aptitude scores. Results point to a 16 cent annual return on each $1 invested in public schools. To the question of whether some school inputs mattered more than others, we find comparable 25–32 cent returns per dollar invested in extended school years, teacher salaries, and smaller classes. School spending and inputs had much more bearing on labor market outcomes than aptitude scores. We document diminishing returns to school expenditures, which, in combination with segregated schools, resulted in higher returns to expenditures in black schools relative to white.     

Accruals Quality,Stock Return Seasonality,and the Cost of Equity Capital: International Evidence

Mashruwala and Mashruwala (2011) argue that inconsistent earlier findings regarding whether accruals quality (AQ) is priced in equity markets (Core, Guay, and Verdi 2008; Kim and Qi 2010) may be explained by seasonality in returns deriving from tax‐loss selling. Finding no evidence of annual AQ premia for U.S. firms, Mashruwala and Mashruwala report that significant monthly premia concentrate in January, with the remainder of the year demonstrating negative or insignificant returns to AQ and attribute this strong seasonality to tax‐loss selling by investors, rather than information risk. However, the end of the tax year for U.S. investors coincides with the calendar year and the financial year for the majority of firms, which may suggest alternative explanations for seasonal variation in returns. We extend Mashruwala and Mashruwala's study, using an international sample including countries where incentives for tax‐loss selling exist, but in which the standard tax and financial years differ (Japan and the United Kingdom), and where the tax and financial years conclude in a month other than December (Australia), as well as employing a longer U.S. sample. We find some evidence of an AQ premium in the United States, which although dominated by January returns, remains significant annually. However, these findings are sensitive to the inclusion of low price stocks and the choice of asset pricing test. In Japan, the United Kingdom, and Australia we document consistent evidence that an AQ premium exists on average throughout the year, and in samples excluding the first month of the tax year. The sensitivity of our U.S. results to the January period may reflect the conflation of numerous seasonal influences on returns, not all of which necessarily reflect mispricing.     

中国证券市场的周期性异象检验

本文分析了6年多来中国证券市场大盘指数和基金指数的周内、月内及年内效应,并对其相互间的关联性进行了检验。实证表明,中国市场存在“周二周四”的周内效应;市场大盘指数2月份的收益率相对最高,基金指数在3月份、12月份的收益率较高,同时大盘指数和基金指数9月份的收益率都显著较低;各指数第三季度收益率相对最低;上半年收益率要高于下半年。联动性检验显示。周二、周四与月内的不同时段交互作用并不显著;周四与10月份对大部分市场大盘指数和基金指数有负的联动效应。     

Agricultural productivity in China

A stylized fact of Chinese agricultural production is a persistently rising cost share of industrial inputs, reflecting the law of diminishing returns. An alternative approach is presented to estimate agricultural productivity by incorporating this characteristic with a CES production function. We find that the elasticity of substitution affects significantly the size of total factor productivity. Our results suggest that the role of industrial inputs may have been underestimated; most of the gain in total factor productivity is attributable to the evolving mix of agricultural output, and the contribution of household farming may not be as large as previously claimed.     

The optimal length of a patent with variable output elasticity and returns to scale in R&D

This paper extends the pure theory of patents to make it consistent with the empirical evidence on R&D which shows both variable returns to scale and a variable elasticity of cost reduction with respect to R&D (output elasticity). Using a generalized invention possibility function, the authors show that for a given social rate of discount, a socially optimal patent depends only on output elasticity and demand elasticity. The authors also show that an optimal patent can exist for increasing returns as well as for constant and decreasing returns to R&D. In general, the constant elasticity assumption overestimates the optimal life of a patent.     

报酬变化规律视角的自然垄断产业规制

报酬递减规律和报酬递增规律共同存在于自然垄断产业发展过程中,并对自然垄断产业产生了不同的影响,进而引发了相应规制的差异性。对报酬递减规律支配型自然垄断产业而言,应以限制性规制为主,建立规制风险预警机制来加以防范规制风险。对报酬递增规律支配型自然垄断产业而言,应以激励型规制为主;并对网络性较强的自然垄断产业实施价格规制,放大整个产业报酬递增规律效应。     

On Constructing an EPS Measure: An Assessment of the Properties of Dilution*

This paper evaluates the information content of the treasury stock method for computing diluted earnings per share (EPS). We demonstrate that the treasury stock method decreases the annual association between earnings changes and stock returns and explain why this is the case. Further, we show that the treasury stock method leads to a dilutive adjustment that biases the random walk model of annual earnings in a predictable direction. Finally, we demonstrate that using the treasury stock method appears to confuse both analysts and investors: analysts' forecast errors increase with the size of the dilutive adjustment, and the association between unexpected earnings and stock returns at the earnings announcement date weakens as the dilutive adjustment increases.     

The reaction of Canadian securities to revisions of earnings forecasts*

Abstract. This first study of Canadian securities' earnings forecasts published by Institutional Brokers Estimate System (IBES) focuses on changes in the mean earnings per share forecasts of 159 to 188 companies from 1985 to 1987. Cumulative average residuals are used to detect the announcement effects of large earnings forecast revisions. The main results of this study are the following. First, an investor with access to changes of earnings per share forecasts at the beginning of the month of publication could realize abnormal excess returns. Second, trading strategies based on earnings forecasts revisions can also yield abnormal returns, but the magnitude of the revision, the sector of the company, and the month in which the revision is realized must be considered. Third, when financial analysts' forecasts are published, the informational content of large revisions in forecasts has already been discounted by the market. This result is similar to findings of U.S.– and U.K.–based studies. Finally, large forecasts revisions coincide with a period of abnormal returns. However, the information content of the announcement of forecasts changes cannot be established. The gains are larger if the trade is undertaken before the diffusion of the forecast revision to the IBES subscribers. These results do not vary with the model chosen to predict company returns. This does not necessarily indicate the existence of a market inefficiency because information acquisition and analysis costs, as well as transaction costs, may diminish considerably these abnormal trading gains.     

The Impact of Research and Development on Economic Growth and Productivity in the U.S. States

Research and development (R&D) has a large effect on both state output and total factor productivity in the long run. Our estimates for the private sector of the U.S. states from 1963 to 2007 show that the R&D elasticity averages 0.056–0.143. The implied returns to state Gross Domestic Product (GDP) from R&D spending are 82–211%. There are also positive R&D spillovers, with 70–80% of the total returns accruing to other states. We also find that states with more human capital have higher own‐ and other‐R&D elasticities, and those in lowest tier of economic development have the least own‐state R&D elasticity but the highest other‐R&D elasticity. In addition, we find that the positive effect of R&D spillovers across states is larger when we consider R&D spillovers across states based on economic similarity of R&D across sectors.     

The Relation between Aggregate Earnings and Security Returns over Long Intervals*

This paper provides a theoretical explanation and consistent empirical evidence for the increase in the contemporaneous correlation between returns and aggregate earnings as the return interval is lengthened. Consistent with intuition and with Easton, Harris, and Ohlson 1992, the analysis shows that aggregation over time renders the lag in accounting recognition relatively less important and thus improves the returns‐earnings R². Interestingly, the analysis also reveals that aggregating earnings over longer periods increases the positive covariance between aggregate earnings and the accounting lag, which may further increase the R². This positive covariance can lead to an earnings coefficient greater than one over some range of aggregation, which is consistent with the findings of Easton et al. that over the 10‐year interval the returns‐earnings regression slope coefficient is greater than one (1.7). The empirical results highlight the fact that the slope coefficient, which is greater than one and increasing with the interval, accounts for much of the increment to the returns‐earnings R². In fact, constraining the slope coefficient to be one results in an R² of 11 percent for the 10‐year interval, which is considerably lower than the R² of 47 percent when the regression is unconstrained. Hence, the positive covariance between current earnings and the accounting lag, rather than the diminishing effect of the accounting lag, appears to be the dominant explanation for the observed high R² over long intervals.     

Arresting the Sword of Damocles: The transition to the post-Malthusian era in Denmark

The Malthusian model is the subject of a fierce debate within economic history. Although the positive causal relationship postulated from living standards to population growth is relatively uncontroversial for preindustrial societies, this cannot be said for the other key relationship, diminishing returns due to fixed supplies of land. We argue that Denmark, which was characterized by extreme resource and environmental constraints until the final decades of the eighteenth century, provides an ideal setting for testing whether any society was ever truly Malthusian. We employ a cointegrated VAR model on Danish data from 1731 to 1800, finding evidence for diminishing returns until ca. 1775. Yet this relationship disappears in the late-eighteenth century, consistent with an increasing pace of technological progress and the emergence of what Unified Growth Theory has termed the “post-Malthusian” era.     

中国城镇居民生活用能和生活垃圾CO2排放测算及影响因素研究

利用IPCC1996经验公式测算了1980-2011年中国城镇居民使用生活能源和生活垃圾填埋分解过程中排放的CO2。人均CO2排放量和人均生活能源CO2排放量呈先下降再上升的趋势,生活垃圾产生的CO2呈先波动上升再趋于平稳的趋势。采用WLS方法分析了其影响因素。城镇居民恩格尔系数和城镇失业率与人均CO2排放量呈负相关关系,人均GDP、第三产业占GDP比例、城镇化水平和城镇居民行为习惯与人均CO2排放量呈正相关关系;城镇居民行为习惯对人均CO2排放量的变化影响最大。     

The Effect of Limited Liability on the Informativeness of Earnings: Evidence from the Stock and Bond Markets*

Previous empirical research on the informativeness of earnings has focused on stockholders, and has not examined differences in earnings' informativeness for stockholders and bondholders. Because stockholders are residual claimants and bondholders are fixed claimants, the informativeness of earnings should differ for these two types of investors. When a firm's default risk is low, changes in its financial condition should be of limited relevance to bondholders, but should be relevant to stockholders. In contrast, as the likelihood of financial distress increases, stockholders' limited liability allows them to abandon the firm to the bondholders (Fischer and Verrecchia 1997). Accordingly, as a firm's default risk increases, changes in its financial condition should be increasingly important to bondholders and less important to shareholders. Because earnings provide information on firm value, the stock return-earnings association should decrease as the firm's financial strength declines, while the bond return-earnings association should increase. We use two measures of a firm's financial strength: the firm's bond rating and its reporting of a loss. Consistent with our hypotheses, we find that the association between stock returns and changes in annual earnings decreases as bond ratings decline, while the association between bond returns and changes in annual earnings increases. These results suggest that as the company's financial condition deteriorates, earnings become less relevant for stock valuation and more relevant for bond valuation. When we partition firms based on their loss status, we find a stronger association between stock returns and annual earnings changes for firms with positive earnings (profit firms) than for firms with losses, consistent with earlier studies. In contrast, we find that the association between bond returns and earnings changes is greater for loss firms than for profit firms. These results suggest that losses reduce the informativeness of earnings for stockholders but increase informativeness for bondholders, suggesting that investors view losses as indicating increased credit risk.     

Returns to education among the informally employed in Thailand

Thailand experienced rapid economic development and made significant investments in education over the past four decades; however, more than half of Thai workers remain informally employed. Despite the prevalence and persistence of informal work in Thailand, little is known about the returns to investments in formal education among informal workers. Using individual-level data from the 2011, 2013, and 2015 Thailand Household Socio-economic Surveys, this study estimates the wage returns to years of education for informal workers using an instrumental variable (IV) approach to correct for potentially biased coefficient estimates on years of education due to unobserved ability. Contrary to expectations, informally employed Thai workers find substantial returns to investments in formal education. The results under the IV approach indicate that the return to an additional year of education for the informally employed is 11–12 per cent, compared to almost 15 per cent for formally employed private firm workers.     

Demand for kerosene in developing countries: A case of Indonesia

This paper attempts to examine the determinants of kerosene consumption in Indonesia. Derived from annual data for the period 1957–1992, the statistical results suggest that in addition to the past conditions, the price of kerosene, price elasticity, and the per capita income are the main determinants of kerosene consumption in Indonesia. The estimated cross-elasticity value with respect to the price of elasticity implies that electricity is a weak substitute for kerosene.     

Measuring poverty with noisy and corrected estimates of annual consumption: Evidence from Nigeria

An opportunity to improve measurement and modelling of poverty in Africa arises from recent intra‐year panel surveys that observe household consumption in post‐planting and post‐harvest periods. Observing the same household twice lets an intra‐year correlation be estimated, which can be used to form a corrected estimate of annual consumption. The usual approach surveys consumption for just one short period, like a week or month, and extrapolates to an annual total. This may adequately estimate mean annual consumption for samples spread over a year but overstates dispersion. The resulting noise in consumption estimates inflates measures of poverty and inequality and creates misclassification errors that bias logit and probit models of poverty determinants. This study uses data from the 2012/2013 Nigeria General Household Survey panel to show effects on poverty measures of using annual estimates extrapolated from short‐period surveys. With the corrected extrapolation method that uses intra‐year correlations to adjust for inflated variances, Nigeria's poverty headcount rate falls by one half. Hence, much of the poverty measured in cross‐sectional surveys is transient poverty, for which different policy interventions are needed than for alleviating chronic poverty.     

The response of aggregate production to fertility-induced changes in population age distribution

With a particular focus upon long-term supply effects, the authors explored the implications of different population age distributions for the productive capacity of an economy. A multilevel aggregate production process was specified, plausible values assigned to its parameters, and steady-state solutions obtained under a range of alternative fertility assumptions. The theoretical model was calibrated to conform with Canadian data and published estimates of age-sex substitution elasticities. The study found productive capacity to be related to age distribution, although the output effects exceed 8%, regardless of the structure of the economy, only when total fertility rate is less than 1.6 or well above 3.0; within the range of variation, productive capacity and output per capita are lower for both younger and older populations; altering the elasticity of substitution between different tasks has negligible effects upon the sensitivity of the economy to changes in age distribution; altering the elasticity of substitution between different age-sex groups for a given task has a markedly greater effect; introducing either increasing or decreasing returns to scale has only a minor effect upon the sensitivity of the economy to changes in age distribution; and marginal products are quite sensitive to changes in age distribution for both younger and older workers, but far less sensitive for middle-aged workers.     

The times they are not changin’: Days and hours of work in Old and New Worlds, 1870–2000

This paper brings a historical perspective to debates on worktime differences across OECD countries, exploiting new data sets on hours of work per week, and days and hours of work per year between 1870 and 2000. We contest the popular view that the divergence in worktimes between Europe and North America and Australia is a recent phenomenon. Since 1870 the decline in weekly and annual hours was consistently greater in the Old World; the New World has had fewer days off for the last 130 years. Labor power and inequality, held to be important determinants of worktime after 1970, had comparable effects in the period before 1913. We find that given their levels of income in 1870 New World workers supplied relatively too many hours of work.     

Investors' Misweighting of Firm-Level Information and the Market's Expectations of Earnings

Prior studies use fundamental earnings forecasts to proxy for the market's expectations of earnings because analyst forecasts are biased and are available for only a subset of firms. We find that as a proxy for market expectations, fundamental forecasts contain systematic measurement errors analogous to those in analysts' biased forecasts. Therefore, these forecasts are not representative of investors' beliefs. The systematic measurement errors from using fundamental forecasts to proxy for market expectations occur because investors misweight the information in many firm-level variables when estimating future earnings, but fundamental forecasts are formed using the historically efficient weights on firm-level variables. Thus, we develop an alternative ex ante proxy for the market's expectations of future earnings (“the implied market forecast”) using the historical (and inefficient) weights, as reflected in stock returns, that the market places on firm-level variables. A trading strategy based on the implied market forecast error, which is measured as the difference between the implied market forecast and the fundamental forecast, generates excess returns of approximately 9 percent per year. These returns cannot be explained by investors' reliance on analysts' biased forecasts. Overall, our results reveal that market expectations differ from both fundamental forecasts and analysts' forecasts.