Output Mix Research Articles

Do Diagnosis-Related Group-Based Payments Incentivise Hospitals to Adjust Output Mix?

This study investigates whether the diagnosis-related group (DRG)-based payment method motivates hospitals to adjust output mix in order to maximise profits. The hypothesis is that when there is an increase in profitability of a DRG, hospitals will increase the proportion of that DRG (own-price effects) and decrease those of other DRGs (cross-price effects), except in cases where there are scope economies in producing two different DRGs. This conjecture is tested in the context of the case payment scheme (CPS) under Taiwan's National Health Insurance programme over the period of July 1999 to December 2004. To tackle endogeneity of DRG profitability and treatment policy, a fixed-effects three-stage least squares method is applied. The results support the hypothesised own-price and cross-price effects, showing that DRGs which share similar resources appear to be complements rather substitutes. For-profit hospitals do not appear to be more responsive to DRG profitability, possibly because of their institutional characteristics and bonds with local communities. The key conclusion is that DRG-based payments will encourage a type of 'product-range' specialisation, which may improve hospital efficiency in the long run. However, further research is needed on how changes in output mix impact patient access and pay-outs of health insurance.

Are All U.S. Credit Unions Alike? A Generalized Model of Heterogeneous Technologies with Endogenous Switching and Fixed Effects

This paper formally models heterogeneity in credit unions’ production technologies as evidenced by (endogenously selected) differing output mixes. We show that failure to account for this observed heterogeneity is likely to lead to biased, inconsistent estimates of credit unions’ technology and potentially misleading results about the industry structure. The estimates are also likely to be biased if one overlooks unobserved credit union specific effects, as customarily done in the literature. To address these concerns, we develop a generalized model of endogenous switching with polychotomous choice that is able to accommodate fixed effects in both the technology selection and the outcome equations. We use this model to estimate returns to scale for the U.S. retail credit unions from 1994 to 2011. Unlike recent studies, we find that not all credit unions enjoy increasing returns to scale. A non/negligible number of large institutions operate at decreasing returns to scale, indicating that they should either cut back in size or switch to a different technology by adjusting the output mix.

Spectrally Equalized Frequency Comb Generation in Multistage Parametric Mixer With Nonlinear Pulse Shaping

A novel approach to improve the flatness of wide-band parametric frequency combs is presented. The method relies on nonlinear pulse shaping prior to parametric mixing in a comb-generating device. The parametric comb is generated in a cavity-less multistage shock-wave mixer, using continuous-wave (CW) laser as comb seed. The pulse shaping is accomplished in a regenerative stage incorporating nonlinear optical/amplifying loop mirror (NOLM/NALM) and provides near-ideal seeds for spectrally equalized frequency comb generation in the output mixing stage. The new technique was implemented separately on two comb generators with a coarse (100 GHz) and dense (10 GHz) tone spacing. A 4 dB flatness over 100 nm is achieved with wide-pitched comb, while the fine-pitched device yielded 1500 tones and possessed sub-2 dB spectral flatness over 120 nm bandwidth.

The Role of Beneficiary Engagement in Performance and Impact Measurement in Social Enterprises

Performance measurement is increasingly important within the field of social enterprise. There are a number of methods for measuring performance and impact and in this paper we specifically investigate whether social enterprises are measuring outputs only or a mix of outputs and outcomes, and whether beneficiaries and funding affect measurement. This mixed methods pilot study addresses the question: How does beneficiary engagement within a social enterprise and the initial type of funding a social enterprise receives affect how it measures performance and impact? In analyzing forty-one cases of social enterprises we found a significant positive relationship between beneficiary engagement and the type of performance measurement utilized. This relationship appeared to be mediated by the initial source of funding; with self-funded social enterprises less likely to measure outcomes than those receiving early external funding.

OPTIMIZACIÓN DE LA PRODUCCIÓN DESDE UNA PERSPECTIVA SOSTENIBLE

ABSTRACT: This work analyzes some implications of environmental constraints on production planning since the entry into force of the Kyoto Protocol. Under an integrated approach we apply a linear programming model that reflects the company productive limitations to obtain the optimal output mix that maximizes profit, including CO2 emissions constraints. To illustrate the application of the model an example has been applied to one of the sectors affected. The information provided by the optimal program has been differentiated whether the optimal program involves the total or partial consumption of emission allowances available and whether included in the model the estimated market price of emission allowances. The results obtained showed that the model used is sensitive to the variation of the parameters considered, highlighting the role that the emissions allowances available and the price of them in CO2 emissions market. Also, the sensitivity analysis allowed us to show the effect of variations in the parameters considered in the model on the production plan. Key Words: production planning, linear programming, environmental management, Protocol Kyoto, CO2 emissions, emission allowances

Severity of illness in the case-mix specification and performance: A study for Italian public hospitals

Background: Public hospitals’ expenditures in Italy is approximately 45% of total public health financing. The reduction of public debt requires reducing total public health, as well as hospital expenditures in the public sector. Past health reforms introduced rules to improve the efficiency in controlling hospital costs with a better use of resources. The objective of this study is to derive technical efficiency as a performance measurement in the directly managed public hospitals in Italy under different case-mix specifications, as well as to discover the effect of it on technical efficiency. Methods: Two different Data Envelopment Analysis (DEA) models are solved. To control for the influence of the case-mix complexity/severity of illness on technical efficiency, the distributions of DEA efficiency scores are compared applying statistical tests developed in the non-parametric efficiency analysis. Results: On average, in the year 2007, the technical efficiency in the sample is lower (0.8071) in model B (output mix with weighted Case Mix Index) than in model A (0.8748). The bootstrap-corrected efficiency scores of models B and A are respectively 0.7185 and 0.8106. On average, the case mix index in the sample is 0.87859. Statistical tests confirm that the differences in the efficiency scores distribution are statistically significant, confirming that treatment complexity has influenced technical efficiency. At the individual hospital level, the effect is more evident, modifying the rank and the technical efficiency of the hospitals. Conclusions: The different case-mix specifications adjusted with Case Mix Index, generate statistically significant differences in the distribution of the efficiency scores. This evidence permits us to conclude that the performance of the Local Health Trust’s directly managed public Italian hospitals is influenced by the hospitals’ case-mix severity/complexity. As a policy indication, we can observe that the need for policy makers and hospital managers to reduce hospital costs conflicts with the need to guarantee an optimum level of hospital resources with different case-mix complexities of the treated cases.

Estimating most productive scale size with double frontiers data envelopment analysis

In this paper, most productive scale size (MPSS) for input and output mixes is measured from pessimistic point of view by using pessimistic data envelopment analysis (DEA). It is proved that the decision making unit (DMU) with the maximum pessimistic efficiency represents MPSS. However, the optimistic and the pessimistic measurements may identify different DMU as MPSS. To find the optimal DMU that represents MPSS, a double frontiers approach is developed by using the Hurwicz criterion to integrate both the information on the optimistic and the pessimistic frontiers. Numerical examples are provided to show the applications of the proposed methods in estimating MPSS.

Comparing Research Productivity Across Disciplines and Career Stages

In academia, productivity continues to be a major factor in decisions of salary raises as well as promotion. The current study thus examines and compares the research productivity of faculty members across disciplines and career stages. The research tests three life course theories (cumulative advantage, utility maximization theory and obsolescence theory) with data from eight disciplines (biology, computer sciences, mathematics/statistics, physical sciences, psychology, social sciences, engineering, and health fields). The data for this study are taken from the 2003 Survey of Doctorate Recipients. Unlike past studies, which solely use journal articles as a measure of research productivity, this study also takes into consideration publications in books and monographs. The study found that the majority of the research output (articles and books) produced in Health and Physical Sciences disciplines is by early and mid career faculty members, providing support for the obsolescence theory, which suggests that research performance declines as faculty members progress in their careers. Further, aging shifts the output mix more towards books for social scientists, making them the most productive group when books or monographs are taken as a measure of research productivity.

Comparing health outcomes among hospitals: the experience of the Lombardy Region

In recent years, governments and other stakeholders have increasingly used administrative data for measuring healthcare outcomes and building rankings of health care providers. However, the accuracy of such data sources has often been questioned. Starting in 2002, the Lombardy (Italy) regional administration began monitoring hospital care effectiveness on administrative databases using seven outcome measures related to mortality and readmissions. The present study describes the use of benchmarking results of risk-standardized mortality from Lombardy regional hospitals. The data usage is part of a general program of continuous improvement directed to health care service and organizational learning, rather than at penalizing or rewarding hospitals. In particular, hierarchical regression analyses - taking into account mortality variation across hospitals - were conducted separately for each of the most relevant clinical disciplines. Overall mortality was used as the outcome variable and the mix of the hospitals' output was taken into account by means of Diagnosis Related Group data, while also adjusting for both patient and hospital characteristics. Yearly adjusted mortality rates for each hospital were translated into a reporting tool that indicates to healthcare managers at a glance, in a user-friendly and non-threatening format, underachieving and over-performing hospitals. Even considering that benchmarking on risk-adjusted outcomes tend to elicit contrasting public opinions and diverging policymaking, we show that repeated outcome measurements and the development and dissemination of organizational best practices have promoted in Lombardy region implementation of outcome measures in healthcare management and stimulated interest and involvement of healthcare stakeholders.

Unoriented two-stage DEA: The case of the oscillating intermediate products

Data envelopment analysis (DEA) allows us to evaluate the relative efficiency of each of a set of decision-making units (DMUs). However, the methodology does not permit us to identify specific sources of inefficiency because DEA views the DMU as a “black box” that consumes a mix of inputs and produces a mix of outputs. Thus, DEA does not provide a DMU manager with insight regarding the internal source of the organization’s inefficiency.Recent methodological developments have extended the basic DEA methodology to allow the analyst to “look inside” the DMU and model the network of production processes that comprise the organization. In such models, sub-DMUs consume inputs from outside the DMU and intermediate products from other sub-DMUs to produce outputs that flow out of the DMU and intermediate products that flow into other sub-DMUs. In this paper, we present an unoriented two-stage DEA model to measure efficiency in situations in which analysts seek to simultaneously reduce input quantities and increase output quantities. The methodology extends previous work in which the model must be either input-oriented or output-oriented. The key to the methodology is an iterative algorithm that alternates between an input-oriented “push backward” step and an output-oriented “push forward” step that is characterized by damped oscillations in the intermediate products. We apply the methodology to Major League Baseball teams during the 2009 season to demonstrate how this approach provides a deeper understanding of each team’s operations.

Multi-Product Firms and Product Switching in Japan

This paper explores role of multi-product plants and product switching in the Japanese manufacturing sector. While a substantial body of work has explored the importance of the extensive margins of plant entry and exit in employment and output flows, only recently has research begun to examine the adjustment across products within establishments and its importance for plant and aggregate output and employment flows. Using a novel, annual plant-product data set covering all Japanese manufacturing plants with more than 4 employees from 1992 to 2006, we provide the first evidence on the role of multi-product plants in Japanese manufacturing and how the product mix and the plant mix have changed over time. Unlike previous studies we are able to track annual changes in the product mix. The period covers a major decline in manufacturing activity and we show that the mix of products and output shifted strongly towards larger multi-product plants that are part of multi-establishment manufacturing firms.

The welfare impacts of an invasive species: Endogenous vs. exogenous price models

The “fixed-prices” models used to measure damages from invasive species typically overestimate financial impacts. These fixed-price assessments do not address key behavioral modifications that lower costs as people adapt by changing their mix of inputs and outputs given new economic circumstances. Using the invasive emerald ash borer (Agrilus planipennis) in Ohio as a motivating example, we develop a computable general equilibrium model that accounts for these behavioral responses. We estimate annual damages from the beetle to be about $70million, an order of magnitude less than the $400–$900million in damages estimated using a fixed-price model. Damages are lower because people adapt through price and income adjustments that occur after ash trees are devastated from the emerald ash borer.

Output complexity, environmental conditions, and the efficiency of municipalities

Over the last few years, many studies have analyzed the efficiency of local governments in different countries. An accurate definition of their output bundles—i.e., the services and facilities they provide to their constituencies—is essential to this research. However, several difficulties emerge in this task. First, since in most cases the law only establishes the minimum amount of services and facilities to provide, it may well be the case that some municipalities go beyond the legal minimum and, consequently, might have an uncertain effect on efficiency when compared to other municipalities which stick to the legal minimum. Second, municipalities face very different environmental conditions, which raises some doubts about the plausibility of an unconditional analysis. This study tackles these problems by proposing an analysis in which the efficiency of municipalities is evaluated after splitting them into clusters according to various criteria (output mix, environmental conditions, level of powers). We perform our estimations using order-m frontiers, given their robustness to outliers and immunity to the curse of dimensionality. We provide an application to Spanish municipalities, and results show that both output mix and, more especially, environmental conditions, should be controlled for, since efficiency differences between municipalities in different groups are notable.

Decomposing the impact of alternative technology sets on future carbon emissions growth

What are the drivers of future global carbon dioxide (CO2) emissions growth and how would the availability of key energy supply technologies change their relative importance? In this paper, we apply a novel index number decomposition technique to the results of a multi-region, multi-sector computable general equilibrium model to quantify the influence of five factors on the growth of future carbon emissions: (1) growth in global economic activity; (2) shifts in the regional composition of gross world product; (3) shifts in the sectoral composition of regions' GDP; (4) changes in sectors' energy–output ratios; and (5) changes in the CO2 intensity of energy sources. We elucidate how the relative importance of these factors changes in response to the imposition of a global carbon tax and alternative assumptions about the future availability of key energy supply technologies. Rising global economic activity and shifts in regional composition put upward pressure on emissions while changes in energy and emission intensity and the sectoral output mix have attenuating effects. A global emission tax that increases over time slows economic expansion and shifts the fuel mix, with the most pronounced impacts on China, India, and Russia. Limited availability of carbon capture and storage, nuclear, and hydroelectric generation all lead to upward shifts in the long-run marginal abatement cost curve, causing some countries to choose to pay the tax rather than abate.

Environmental Regulation and Revealed Comparative Advantages in Europe: Is China a Pollution Haven?

AbstractThe relocation of more polluting industries in poorer countries owing to gaps in environmental standards is known as the pollution haven effect, whereby the scale and the composition of output change across countries. Changes in the composition of the output mix might translate into changes of comparative advantages across countries, as revealed by trade flows. This paper focuses on this issue, looking at the changes in the structure of bilateral trade over the period 1996–2006 between China and 14 EU countries (EU14) as a measure of revealed comparative advantage (RCA). Using industry‐level data on bilateral trade, air‐ and water‐pollution intensity, and several measures of environmental stringency, we find that, after controlling for other factors (such as labor costs) on average our EU14 countries have kept or improved their RCA with respect to China in both water‐polluting industries (such as paper and agro‐based) and air‐polluting industries (such as basic metals and chemicals), while they have lost competitiveness in the more clean industries (such as machinery and fabricated metals). Thus, we find no evidence of a pollution haven effect on the bilateral trade pattern between Europe and China.

Scales and technical efficiencies in Middle East and North African (MENA) micro financial institutions

PurposeThe purpose of this paper is to investigate technical and scales efficiencies of MFIs in Middle East and North Africa (MENA) countries in provision of financial services. This study also aims at tracing the source of inefficiencies.Design/methodology/approachThis paper uses the non‐parametric data envelopment analysis (DEA) approach to estimate the production technology for the set of MENA MFIs. The paper uses DEA because it allows us to perform analyses with small samples, which is the case for MENA, and also allows us to calculate Malmquist indexes to characterize productivity changes. Moreover, DEA does not require a production function to calculate the efficiency. It attempts to determine the efficiency of the firm against some imposed benchmark through mathematical programming.FindingsThe paper finds low technical efficiency for all MFIs under both intermediation and the production approaches of DEA methodology. This means that MFIs are wasting input resources (input oriented inefficient) and are not producing enough outputs (making loan, raising funds, and obtaining more borrowers per staff). The paper also does not find any improvement in those efficiencies during the period 2000‐2005.Originality/valueThe study contributes to the existing MFIs literature by pursuing an empirical and decomposition analysis of efficiency by employing two approaches of DEA methodology to trace the sources of inefficiencies which the managers, practitioners and policy makers need to focus on. DEA has been used as a tool to select the right mix of inputs and outputs to assist in tracing the sources of inefficiencies

Economies of scope in distance education: The case of Chinese research universities

<span>With the rapid development of information technologies, distance education has become “another form of product differentiation in the output mix produced by the multi-product university or college” (Cohn & Cooper, 2004, p. 607). This article aims at analyzing the economies of scope of distance education (as an educational output) in Chinese research universities. The empirical results show that a) product-specific economies of scope do exist in distance education programs offered by Chinese research universities; b) there are economies of scale in distance education; and c) there are weak cost complementarities between distance education and research output, meaning that distance education and academic research can promote each other to reduce the costs in Chinese research universities.</span><br /><input id="gwProxy" type="hidden" /><input id="jsProxy" onclick="if(typeof(jsCall)=='function'){jsCall();}else{setTimeout('jsCall()',500);}" type="hidden" />

Modeling international trends in energy efficiency

I use a stochastic production frontier to model energy efficiency trends in 85 countries over a 37-year period. Differences in energy efficiency across countries are modeled as a stochastic function of explanatory variables and I estimate the model using the cross-section of time-averaged data, so that no structure is imposed on technological change over time. Energy efficiency is measured using a new energy distance function approach. The country using the least energy per unit output, given its mix of outputs and inputs, defines the global production frontier. A country's relative energy efficiency is given by its distance from the frontier—the ratio of its actual energy use to the minimum required energy use, ceteris paribus. Energy efficiency is higher in countries with, inter alia, higher total factor productivity, undervalued currencies, and smaller fossil fuel reserves and it converges over time across countries. Globally, technological change was the most important factor counteracting the energy-use and carbon-emissions increasing effects of economic growth.

Are Skills a Constraint on Firms? New Evidence from Russia

The paper uses a unique survey of recruitment firms to look at how Russian firms perceive the supply of skills in the labour market and how well those skills match to their demand for labour. Firms invest significant amounts of time in search to fill vacancies and search time is unambiguously increasing in skills. These skill gaps are associated with significant wage premia and are perceived to have negative consequences for the output mix and productivity. A small job postings experiment also finds that search time increased yet further for activities considered relatively innovative. Further, using Russian Ministry of Labour data for all legal migrant applications in 2010 and matching the migrant to the sponsoring firm, we find that there is some – albeit limited - evidence of firms using migrants to address high skill shortages. However, the overwhelming majority of migrants are skilled or unskilled workers; a reflection of the low underlying rates of innovation and associated demand for high skill jobs.

Grade inflation or productivity growth? An analysis of changing grade distributions at a regional university

We examine departmental grade distributions for the school years 1985–1986, 1995–1996, and 2004–2005 at Southeast Missouri State University. Mean undergraduate grade point averages (GPAs) increased from 2.6 in 1985–1986 to 3.1 in 2004–2005. Although higher student GPAs might be evidence of grade inflation, university departments might have experienced productivity improvements that enhanced student learning, given inputs. We represent the technology by the directional distance function. Departments produce two outputs-grade points earned by students and the information content of those grades-using faculty and student inputs. The entropy index is used to proxy the information content of grade distributions. The estimates indicate; no systematic changes in inefficiency over time; a movement along the production frontier toward a mix of outputs with relative more grade points and less entropy; a shift toward non-tenure track faculty that increases the shadow price of entropy relative to grade points.