Economic importance and statistical significance: Guidelines for communicating empirical research

Abstract

A critical objective for many empirical studies is a thorough evaluation of both substantive importance and statistical significance. Feminist economists have critiqued neoclassical economics studies for an excessive focus on statistical machinery at the expense of substantive issues. Drawing from the ongoing debate about the rhetoric of economic inquiry and significance tests, this paper examines approaches for presenting empirical results effectively to ensure that the analysis is accurate, meaningful, and relevant for the conceptual and empirical context. To that end, it demonstrates several measurement issues that affect the interpretation of economic significance and are commonly overlooked in empirical studies. This paper provides guidelines for clearly communicating two distinct aspects of “significance” in empirical research, using prose, tables, and charts based on OLS, logit, and probit regression results. These guidelines are illustrated with samples of ineffective writing annotated to show weaknesses, followed by concrete examples and explanations of improved presentation.     

A Probit Analysis of Aboriginal Employment Prospects in New South Wales*

Using data from the 1986–87Survey of Working Age Aborigines in New South Wales, this paper presents the results of a probit analysis to determine the characteristics which differentiate employed Aborigines from Aborigines not in employment The results of the probit analysis show the importance of the acquisition of human capital to the employment success of Aborigines, at least in New South Wales. Increments in level of education, previous participation in formal labour market programs, and previous employment experience all have significant, positive impacts on the likelihood of individual Aborigines being in employment     

An Evaluation of the Vanderbilt-JCEE Experimental PSI Course in Elementary Economics

This is considerably longer than articles normally accepted by the JEE, but we considered it to be an important follow-up of our Special Issue No. 2, “The Vanderbilt-JCEE Experimental Course in Elementary Economics.” (Winter 1974.) The authors address a number of aspects of PSI, some of which have rarely been touched upon by other researchers interested in this method. This paper deals not only with student learning and student reactions to PSI, but with its effects on performance in higher level economics courses, its impact on the student proctors in terms of their learning of economics, and the costs of establishing and maintaining a PSI course. Siegfried and Strand have not answered all the questions pertaining to self-paced instruction but, along with Allison, Billings, Fels, Soper, Spector, Tietenberg and others, they have contributed significantly to our knowledge of the effectiveness of PSI.     

Delinquency and gender

The determinants of juvenile delinquency for males and females using the Delinquency in a Birth Cohort II Study are investigated. Ordered probit models for juvenile arrest are estimated separately for males and females. The results indicate that juvenile arrests for both males and females are more likely for non-whites and for those who leave education early. Males and females behave differently, in that males are more likely to be repeat offenders.     

Economic Education in Korea: Current Status and Changes

The authors describe key aspects of precollege and undergraduate economic education in Korea. They show that precollege students seem to have low economics literacy due to problems with the curriculum and insufficient training of teachers. At the undergraduate level, they show that economics departments have more male students than female students and that the employment rate for economics majors is lower than for business majors. They hope to draw more of Korean economists' attention to research initiatives in economic education.     

An Alternative View of Citation Patterns of Quantitative Literature Cited by Business and Economic Researchers

Using nationally representative data, the authors examine the effects of preprofessional education on the earnings of lawyers. They specify and estimate a statistical earnings function on the basis of well-established theory and principles. Along with standard control variables, categorical variables are included to represent graduate degrees in addition to the law degree and an assortment of undergraduate major fields. Holding a Ph.D. or M.B.A. degree, with the law degree, is associated with significantly higher earnings in some sectors. Lawyers with undergraduate training in economics earn more than other lawyers, ceteris paribus, and economics is the only undergraduate field associated with earnings that differ significantly. The available evidence supports the hypothesis that economics training increases a lawyer's human capital compared with other undergraduate majors.     

Why it Pays to Major in Economics

In this article, the authors use a large, recent, and accessible data set to examine the effect of economics major on individual earnings. They find a significant positive earnings gain for economics majors relative to other majors, and this advantage increases with the level of education. Their findings are consistent with Black, Sanders, and Taylor (2003), documenting that about two-thirds of the bachelor's degree premium for economics majors can be attributed to the type of job economics majors perform, and about one-third is a premium that economics majors earn over other workers within the same job.     

HOW GREEN IS YOUR CAMPUS? AN ANALYSIS OF THE FACTORS THAT DRIVE UNIVERSITIES TO EMBRACE SUSTAINABILITY

I examine the factors that influence the adoption of sustainable practices by institutions of higher education (IHEs) in the United States. Using data from the Sustainable Endowments Institute, I conduct an ordered probit analysis on 180 IHEs. The results show that size and wealth are significant factors in the adoption of sustainable practices and that stakeholders such as faculty, alumni, and the surrounding community also play an important role. I find no evidence that institutions adopt sustainability to attract students. Also, in contrast to the findings of similar studies on for‐profit entities, there is no evidence that regulatory pressures encourage campus sustainability. I also examine the factors that affect the institutions' decision to sign the Presidents Climate Commitment (PCC), a largely symbolic gesture. The results for the PCC are quite different than those for overall sustainability. Most importantly, neither wealth nor size are significant factors in that decision. (JEL Q2, L3)     

The Short‐term Determinants of Capital Flows for a Small Open Economy: The Case of Greece

This paper presents the factors driving capital flows inwards and outwards of a small open economy such as Greece during the period 1983–2009. Apart from the determinants of capital flows the possibility of speculative attacks is also considered. Applying the ordinary least squares (OLS) method it is found that variables linked to external factors such as the differential of domestic and foreign interest rates and financial crises, such as the Asian and Russian financial turmoil of 1997 and 1998 respectively, are the main factors influencing capital inflows and outflows in Greece during the period 1983–2009. Additionally the results of probit analysis support that the same factors are significant in determining the probability of speculative attacks to the Greek economy.     

A Cross-Country Comparison of Okun's Coefficient

In this paper Okun's law is tested for the G7 countries in order to compare the responsiveness of unemployment to economic growth. Cyclical unemployment and output are extracted using Harvey's structural time series model. Okun's coefficient is estimated by OLS, rolling OLS, and SUR. The coefficient seems to be highest for North America and lowest for Japan, a result that can be explained in terms of differences in labor market rigidities. The rising absolute value of the coefficients over time indicated by the results of rolling OLS is explained in terms of labor market reform.J. Comp. Econom.,June 1997,24(3), pp. 335–356. La Trobe University, Bundoora, Victoria 3083, Australia.     

Gender differences in e-commerce

Predictors of shopping online were compared for men and women using a sample of 365 college students. For the men, the only predictor of purchasing products online was the number of hours they spent online. For women, the predictors of making purchases online included anxiety about using computers and attitudes toward money, in addition to the number of hours spent online. The results were examined using OLS and MLE (logit and probit) regressions techniques, and the results from each technique compared and contrasted.     

Geographic Differences in the Earnings of Economics Majors

Economics has been shown to be a relatively high-earning college major, but geographic differences in earnings have been largely overlooked. The authors of this article use the American Community Survey to examine geographic differences in both absolute earnings and relative earnings for economics majors. They find that there are substantial geographic differences in both the absolute and relative earnings of economics majors, even when controlling for individual characteristics such as age, education, occupation, and industry. They argue that mean earnings in specific labor markets are a better measure of the benefits of majoring in economics than simply looking at national averages.     

A Discrete-Time Hazard Analysis of the Role of Gender in Persistence in the Economics Major

So much has been done in terms of measuring the impact of economics courses on student knowledge and understanding of facts, concepts and principles, and so little research has dealt with the possible effects on student political attitudes, that this study by Scott and Rothman should be of great interest to economics instructors. The authors address themselves to George Stigler's assertion that “the education of an economist makes the person who receives it more conservative.” They report on the use of their own “Social Opinion Questionnaire” and how it was employed to investigate “the different effects, if any, introductory economics and introductory psychology have on opinions related to economic issues.”     

Predicting Canadian recessions using dynamic probit modelling approaches

Abstract This paper examines the ability of various financial and macroeconomic variables to forecast Canadian recessions. It evaluates four model specifications, including the advanced dynamic, autoregressive, dynamic autoregressive probit models as well as the conventional static probit model. The empirical results highlight several significant recession predictors, notably the government bond yield spread, growth rates of the housing starts, the real money supply and the composite index of leading indicators. Both the in‐sample and out‐of‐sample results suggest that the forecasting performance of the four probit models is mixed. The dynamic and dynamic autoregressive probit models are better in predicting the duration of recessions while the static and autoregressive probit models are better in forecasting the peaks of business cycles. Hence, the advanced dynamic models and the conventional static probit model can complement one another to provide more accurate forecasts for the duration and turning points of business cycles.     

Changing returns to education in Portugal during the 1980s and early 1990s: OLS and quantile regression estimators

This paper examines the evolution of the returns to education in Portugal over the 1980s and early 1990s. The main findings indicate that the returns to education have increased, particularly after joining the European Union in 1986. Since this occurred along with an increase in the level of education within the labour force, the process is most likely demand driven. The results also indicate that modelling on average (i.e. OLS) misses important features of the wage structure. Quantile regression (QR) analysis reveals that the effect of education is not constant across the conditional wage distribution. They are higher for those at higher quantiles in the conditional wage distribution. Wage inequality expanded in Portugal over the 1980s and the returns to education had an important role in this process.     

Endogenous schooling and the distribution of the gender wage gap

Previous studies on the gender wage gap have relied on OLS when estimating the wage equations. However, a number of recent studies, devoted to estimating the return to education, have shown that OLS may produce biased estimates for a number of reasons. As a consequence, previous results regarding the gender wage gap may also be biased. In this paper, we first estimate wage equations using a GMM procedure applied to panel data and then investigate the distribution of the gender wage gap. The results indicate that OLS may seriously overestimate the unexplained gender wage gap.First version received: October 2001/Final version accepted: July 2003     

RIDGE ESTIMATORS FOR PROBIT REGRESSION: WITH AN APPLICATION TO LABOUR MARKET DATA

In this paper we propose ridge regression estimators for probit models since the commonly applied maximum likelihood (ML) method is sensitive to multicollinearity. An extensive Monte Carlo study is conducted where the performance of the ML method and the probit ridge regression (PRR) is investigated when the data are collinear. In the simulation study we evaluate a number of methods of estimating the ridge parameter k that have recently been developed for use in linear regression analysis. The results from the simulation study show that there is at least one group of the estimators of k that regularly has a lower mean squared error than the ML method for all different situations that have been evaluated. Finally, we show the benefit of the new method using the classical Dehejia and Wahba dataset which is based on a labour market experiment.     

Educational choice, wage determination, and rates of return to education in Taiwan

This paper estimates educational choice, wage determination, and the rate of return to education in Taiwan using Taiwan's Manpower Utilization Survey data of 1996. As education investment is a self-selection process, this paper adopts a two-stage estimation method. First, a polychotomous ordered probit model is used to estimate the education decision. Second, the wage equations of different educational attainments are estimated by incorporating the possible selection bias obtained in the probit model. Finally, rates of return on each education level are calculated from the estimation results.     

Economic Education in Schools and Universities in England

The authors review three aspects of economic education in England. They examine trends in undergraduate economics in England, principally in terms of recruitment and outcomes and connections with economics in schools. They also review formal instruction in schools through so-called “advanced level” courses for 16–19-year-old students and the role of the academic community in recent research in England on economic education.