growth and profitability of small and medium sized enterprises some welsh evidence foreman peck j makepeace g and morgan b 2006 growth and profitability of small and medium sized enterprises some welsh evidence regional studies 40 307 319 policy makers throughout the organization for economic co operation and development oecd are keen to promote the development of small and medium sized enterprises smes by a wide variety of means the present study of over 1600 welsh smes casts doubt on the effectiveness of doing so by grants by encouraging trade associations by pursuing current initiatives in training or by stimulating innovation as defined by sme management on the other hand it finds that support for selective information technology investment and for marketing planning could be beneficial additional results that might be addressed by policy are short termism by older managers preferring current to future profits more than younger managers signs that fixed costs of tax compliance bear substantially more heavily on the profitability of smaller smes and evidence

estimating demand for local telephone service with asymmetric information and optional calling plans in this paper i study the theoretical and econometric implications of agents uncertainty concerning their future consumption when a monopolist offers them either a unique mandatory nonlinear tariff or a choice in advance from a menu of optional two part tariffs agents uncertainty is resolved through individual and privately known shocks to their types in such a situation the principal may screen agents according to their ex ante or ex post type by offering either a menu of optional tariffs or a standard nonlinear schedule the theoretical implications of the model are used to evaluate a tariff experiment run by south central bell in two cities in kentucky in 1986 the empirical approach explicitly accounts for the existence of informational asymmetries between local telephone users and the monopolist leading to different nested econometric specifications under symmetric and asymmetric information the empirical evidence suggests that there exists a significant asymmetry of information between consumers and the monopolist under both tariff regimes all expected welfare components failed to increase with the introduction of optional tariffs for the estimated value of the parameters copyright 2002 wiley blackwell

pricing and the news vendor problem a review with extensions in the newsvendor problem a decision maker facing random demand for a perishable product decides how much of it to stock for a single selling period this simple problem with its intuitively appealing solution is a crucial building block of stochastic inventory theory which comprises a vast literature focusing on operational efficiency typically in this literature market parameters such as demand and selling price are exogenous however incorporating these factors into the mode l can provide an excellent vehicle for examining how operational problems interact with marketing issues to influence decision making at the firm level in this paper we examine an extension of the newsvendor problem in which stocking quantity and selling price are set simultaneously we provide a comprehensive review that synthesizes existing results for the single period problem and develop additional results to enrich the existing knowledge base we also review and develop insight into a dynamic inventory extension of this problem and motivate the applicability of such models

a single period inventory placement problem for a supply system with the satisficing objective abstract consider the inventory placement problem in an n stage supply system facing a stochastic demand for a single planning period each stage is a stocking point holding some form of inventory e g raw materials subassemblies product returns or finished products that after a suitable transformation can satisfy demand stocking decisions are made before demand occurs unsatisfied demands are lost the revenue salvage value ordering transformation and lost sales costs are proportional there are fixed costs for utilizing stages for stock storage the objective is to maximize the probability of achieving a given target profit level we prove the existence of optimal stocking decisions where at most three stages receive nonzero stocks we also characterize properties of the optimal stocking decisions and provide an o n 3 algorithm for their computation for the special case where all fixed costs are zero the stages utilized do not depend on the demand distribution or the target level and one can find optimal stocking decisions by performing a simple o n 2 search and solving a single variable optimization problem

from plan to plant effects of certification on operational start up in the emergent independent power sector in this paper we study the transition from planned venture to operational start up in the emergent independent power sector planned ventures face tremendous obstacles in assembling the resources necessary to begin operations we hypothesize and show that formal certification from authorized actors increases the likelihood of making this transition moreover we find that the effects of certification are contingent on the legitimacy of the sector as a whole certifications have a stronger effect on start ups when sector legitimacy is low than when it is high this research helps us understand a rarely studied organizational transition from entrepreneurial intention to actual operations within nascent sectors it directs attention to the legitimating effects of formal certification highlights the importance of a multilevel approach to legitimacy and contributes to the growing rapprochement between entrepreneurial studies and institutional theory

interdependency of natural gas network and power system security this paper proposes an integrated model for assessing the impact of interdependency of electricity and natural gas networks on power system security the integrated model incorporates the natural gas network constraints into the optimal solution of security constrained unit commitment the natural gas network is modeled by daily and hourly limits on pipelines sub areas plants and generating units the application of fuel diversity e g generating units with fuel switching capability is presented as an effective peak shaving strategy for natural gas demand which could hedge price volatilities of natural gas and electric power the proposed model can be used by a vertically integrated utility for the commitment and dispatch of generating units and the allocation of natural gas for the next day utilization the proposed model can also be used for measuring the security of social services by modeling the interdependency of natural gas and electric power system infrastructures if the proposed model is used by gencos gas constraints will be submitted to electricity markets as energy constraints illustrative examples show the impact of natural gas supply infrastructure on the economic operation of a vertically integrated utility the examples also discuss the impact of generating units with fuel switching capability on the power system security when the supply of natural gas is limited

an intertemporal model of industrial exit a finite horizon model of industrial exit is developed after an initial lag most exits are by young firms the duration of the lag is positively related to sunk entry costs but not due to the fallacy of sunk costs the conception of entry differs from previous research as a result not all entrants are identical and firm size affects the rate of learning on average larger new firms last longer entrepreneurs in declining firms act more lazily as the firm declines a number of empirical observations about declining firms are organized by the model

generalising gibrat using chinese evidence founded on fieldwork this paper reports on determinants of small firm growth and survival using fieldwork evidence collected by face to face and telephone interviews it extends the basic size age model to a comprehensive growth model with two types of additional explanatory variables firm specific and business environmental estimation is by log linear regression on chinese cross section data with corrections for sample selection bias and heteroskedasticity our results from the comprehensive model highlight the importance of location choice and customer orientation for the growth of chinese private firms

why have urban poverty and income inequality increased so much argentina 1991 2001 abstract this article analyzes the trends in income inequality and poverty among argentine households during the nineties we assess the effect of changes in labor force participation unemployment educational levels and returns to individual characteristics on income inequality and poverty by using a microsimulation approach we found that unemployment accounts for a large part of the increase in income inequality and poverty experienced in the past decade changes in labor force participation had an equalizing effect over the whole period while changes in the returns to workers sociodemographic characteristics could be associated with a small increase in income inequality with respect to poverty unemployment affected negatively the proportion of households below the poverty line amplified the poverty gap and increased the severity of poverty in contrast changes in labor force participation are associated with a reduction in the poverty rate

individual and opportunity factors influencing job creation in new firms we build on multiple theoretical perspectives to investigate the unique and joint effects of individual and opportunity level factors affecting job creation in new firms we tested hypotheses using survey data from individuals who transitioned from unemployment to self employment under the auspices of a german public policy program our findings reveal that an entrepreneur s breadth of knowledge has a negative influence on the firm s job creation whereas the entrepreneur s leadership experience has a positive influence however as the sector specific labor requirements of a business opportunity increase both breadth of knowledge and leadership experience allow founders to operate their firms with fewer employees

the impact of education experience and inner circle advisors on sme performance insights from a study of public development centers in this study we investigate the effects of entrepreneurial human capital on sme performance using data on 2 713 smes within the european union performance was measured in two ways profitability as roa and productivity as revenue per employee results indicate that both profitability and productivity are positively related to industry specific knowledge possessed by the ceo owner prior to starting up the firm and the general business knowledge acquired once the firm is up and running experience as a result of having previously worked in a firm in the same industry before starting a business was related to productivity but there is no relation with profitability there is a link between performance and inclusion of other ceo owners in the founder s inner circle of advisors this relationship is positive when the advisor s venture has experienced failure and negative when the advisor s venture has been successful we discuss the significance of these findings for research and practice

trade protection and industry wages in india this paper examines the link between trade protection and industry wage premia in india using a unique dataset combining employment survey data with industry level data for various years between 1983 and 2000 the author finds that india s trade reforms were not distributionally neutral the impact of protection on industry wage premia was positive and statistically significant though modest in magnitude workers employed in industries with high tariffs received higher wages than apparently identical workers in low tariff industries because industries with high initial levels of protection were also those with the largest tariff reductions during this period and had the highest share of unskilled workers the positive tariff wage effect implies that the trade reforms were likely to have increased wage inequality as the relative wages of the predominantly unskilled workers in these manufacturing industries fell

longitudinal analysis of relationships between planning and performance in small firms this paper investigates causal relationships between planning and performance utilizing a longitudinal database with responses from the same 2 956 businesses over a four year period results confirm the association between planning activity and performance that is evident in most extant literature they also however cast doubt on the traditional perception of the causal sequence of that association although subject to a number of limitations the results indicate that planning is more likely to be introduced into a small firm after a period of growth rather than before a period of growth these results make an important contribution to understanding the planning performance relationship for two main reasons they overcome the static data and relatively smaller sample size restrictions of many past studies and they provide evidence concerning the sequence of the relationship between planning and performance

staying in business abstract the paper analyses factors which help a small entrepreneurial firm to stay in business the time scale for the analysis is three years 1985 1988 the main issue that the paper is concerned with is the role of market and financial variables primary source data are used an estimated probit model indicates that for this sample product range and gearing are the key maket and financial variables respectively the greater the product range and the lower the gearing ceteris paribus the better the chances of staying in business

would nonprofit workers accept to earn less evidence from france this article focuses on wage differentials between french nonprofit for profit and public sectors considering the public sector allows testing more extensively the labour donation theory preston 1989 the findings support this theory because nonprofit workers accept to earn significantly less than they would earn in the for profit and public sectors they also suggest differences in the motivations of workers in these sectors nonprofit workers are attracted to their work for reasons transcending material compensation

do the near elderly value mortality risks differently wage hedonic models are estimated with the health and retirement study to measure the risk wage tradeoffs value of statistical lives for older workers the analysis explicitly allows for multiple employment states including retirement using a multinomial selection model the results suggest that the oldest and most risk averse workers require significantly higher not lower compensation to accept increases in job related fatality risks

a quantitative content analysis of the characteristics of rapid growth firms and their founders a group of firms that is attracting attention are rapid growth firms these firms are of particular interest because rapid growth is an indication of market acceptance and firm success by studying rapidgrowth firms researchers can help all firms better understand the attributes associated with firm growth despite these positive outcomes however rapid firm growth is difficult to achieve and maintain this study adds to the literature through a quantitative content analysis of the narrative descriptions of 50 rapid growth firms and a comparison group of 50 slow growth companies the purpose of the study was to draw from the narratives a list of empirically grounded growth related attributes that are associated with rapid growth firms the findings of the study resulted in the advancement of a conceptual model of the attributes of rapid growth firms in four areas founder characteristics firm attributes business practices and human resource management hrm practices

using trivariate copulas to model sample selection and treatment effects simultaneous nonlinear econometric models with discrete outcomes are often difficult to implement this article considers the use of the copula approach for a model with three jointly determined outcomes it also deals with the discrete case in which outcomes include a mixture of dichotomous choices and discrete count data we apply this technique to study self selection and interdependence between health insurance and health care demand among married couples the full model consists of a dichotomous choice equation for family insurance and a separate negative binomial equation for each spouse s health care use

premiums to employment in larger establishments evidence from peru abstract examination of the employer size wage effect for males in urban peru suggests the following higher wages in larger establishments do not merely compensate for higher worker quality or inferior working conditions size differences in the use of rising wage tenure profiles cannot provide a market clearing explanation for the employer size wage effect unless workers are extremely impatient thus larger employers appear to pay premiums unionization explains none of the premiums and minimum wage compliance explains at best a small fraction shirking based efficiency wage explanations for premiums are implausible because peruvian job security legislation greatly inhibits dismissals in larger establishments explanations meriting further research involve the use of high wages to reduce turnover and to improve productivity enhancing morale

crossing the border self selection earnings and individual migration decisions many empirical studies on the determinants of international migration flows rely exclusively on macro data and do not account for migrants self selection we analyze a very interesting episode in international migration for which we are able to gather individual level data covering all relevant countries namely the exodus of ecuadorians to spain and the us in the aftermath of the economic collapse of 1999 specifically we produce selection corrected predictions of counterfactual individual earnings and use them to estimate a discrete choice migration equation that allows for correlated errors across destinations and a rich structure of migration costs we find that earnings significantly shape individual migration decisions even in an episode in which ecuadorians mostly chose spain where earnings were lower than in the us and they contribute to explaining the observed composition of migration flows moreover our estimates show that changes in earnings at a particular destination have a larger effect on destination choice conditional on migration than on the scale of migration

evaluation of swedish youth labor market programs this paper evaluates two swedish active labour market programmes for youth namely youth practice and labour market training a non parametric matching approach is applied to estimate the average p

does more mean worse three decades of enterprise policy in the tees valley this paper argues that there have been three distinct phases of enterprise policy in the uk in the past 30 years the 1970s saw no effective enterprise policy policy off the 1980s witnessed an attempt to increase the number of start ups and the 1990s saw a concentration on business quality this paper looks at how enterprise has evolved in cleveland tees valley over the past three decades it suggests and finds that businesses in the 1980s were more numerous but of lower quality even if the influence of unemployment is accounted for than those from the 1970s and 1990s this implies that we should be cautious about the value of policy attempts to increase business formation rates in areas such as cleveland tees valley

genco s risk based maintenance outage scheduling this paper presents a stochastic model for the optimal risk based generation maintenance outage scheduling based on hourly price based unit commitment in a generation company genco such maintenance outage schedules will be submitted by gencos to the iso for approval before implementation the objective of a genco is to consider financial risks when scheduling its midterm maintenance outages the genco also coordinates its proposed outage scheduling with short term unit commitment for maximizing payoffs the proposed model is a stochastic mixed integer linear program in which random hourly prices of energy ancillary services and fuel are modeled as scenarios in the monte carlo method financial risks associated with price uncertainty are considered by applying expected downside risks which are incorporated explicitly as constraints this paper shows that gencos could decrease financial risks by adjusting expected payoffs illustrative examples show the calculation of genco s midterm generation maintenance schedule risk level hourly unit commitment and hourly dispatch for bidding into energy and ancillary services markets

does it pay to attend an elite private college cross cohort evidence on the effects of college type on earnings although a substantial and rising labor market premium is associated with college attendance in general little is known about how this premium varies across institutions of different types and across time in this paper we explicitly model high school students choice of college type characterized by selectivity and control based on individual and family characteristics including ability and parental economic status and an estimate of the net costs of attendance we estimate selectivity corrected outcome equations using data from both the national longitudinal study of the high school class of 1972 and high school and beyond which permit us to determine the effects of college quality on wages and earnings and how this effect varies across time even after controlling for selection effects strong evidence emerges of a significant economic return to attending an elite private institution and some evidence suggests this premium has increased over time

security constrained unit commitment with ac constraints in a restructured power market the independent system operator iso executes the security constrained unit commitment scuc program to plan a secure and economical hourly generation schedule for the day ahead market this paper introduces an efficient scuc approach with ac constraints that obtains the minimum system operating cost while maintaining the security of power systems the proposed approach applies the benders decomposition for separating the unit commitment uc in the master problem from the network security check in subproblems the master problem applies the augmented lagrangian relaxation lr method and dynamic programming dp to solve uc the subproblem checks ac network security constraints for the uc solution to determine whether a converged and secure ac power flow can be obtained if any network violations arise corresponding benders cuts will be formed and added to the master problem for solving the next iteration of uc the iterative process will continue until ac violations are eliminated and a converged optimal solution is found in this paper a six bus system and the ieee 118 bus system with 54 units are analyzed to exhibit the effectiveness of the proposed approach

a single period inventory placement problem for a supply chain with the expected profit objective consider the expected profit maximizing inventory placement problem in an n stage supply chain facing a stochastic demand for a single planning period for a specialty item with a very short selling season each stage is a stocking point holding some form of inventory e g raw materials subassemblies product returns or finished products that after a suitable transformation can satisfy customer demand stocking decisions are made before demand occurs because of delays only a known fraction of demand at a stage will wait for shipments unsatisfied demand is lost the revenue salvage value ordering shipping processing and lost sales costs are proportional there are fixed costs for utilizing stages for stock storage after characterizing an optimal solution we propose an algorithm for its computation for the zero fixed cost case the computations can be done on a spreadsheet given normal demands for the nonnegative fixed cost case we develop an effective branch and bound algorithm

trajectories of small business financial structure a dynamic theory of the small firm is expounded assuming entrepreneurs maximise business value over a finite time horizon predicted trajectories for key financial variables are seen to depend on whether debt or equity are cheaper the predicted trajectories are compared with actual trajectories using empirical evidence from three years of detailed primary source data on one hundred and fifty new business startups in scotland evidence largely confirms predictions of the model for the cheap equity case for this case as capital and sales rise steadily debt is retired rapidly except when interest rates on long term debt are low this finding is supported by explicit empirical trajectories of key financial variables

the taxation of drivers and the choice of car fuel type in this paper the choice of the car fuel type is studied in the dutch situation three types are important gasoline diesel and lpg with 80 of the cars using gasoline incentives for using diesel or lpg are provided by the tax system that implies higher fixed cost but lower variable cost for users of these fuel types we start by studying fuel type choice on the basis of a logit model and move on to estimate demand functions for kilometres driven for social purposes while correcting for the possible selectivity bias we find that diesel and lpg are in general regarded as inferior alternatives but that monetary incentives are sufficiently strong to overcome this hurdle for drivers with a large demand for kilometres we also find that there are significant effects of the lower variable cost for diesel and lpg drivers on their demand for kilometres the conclusions are confirmed by estimation of a structural model in which fuel type choice and demand for kilometres are consistently explained on the basis of one set of preferences and unobserved heterogeneity is taken into account

exercise of market power on ramp rate in wind integrated power systems with an increasing penetration of wind power there is likely to be an increasing need for fast ramping generating units these generators ensure that no load is lost if supply drops due to the uncertainties in wind power generation however it is observed in practice that in a presence of network constraints fast ramping generating units are prone to act strategically and exercise market power by withholding their ramp rates in this paper we model this gaming behavior on ramp rates we assume a market operator who collects bids in form of marginal costs quantities and ramp rates he runs a ramp constrained economic dispatch given the generators bids forecasted demand and contingencies following the game theoretic concepts we set up a multi level optimization problem the lower level problem is the ramp constrained economic dispatch and the higher level represents the profit maximization problems solved by strategic generators the whole problem is formulated as an equilibrium problem with equilibrium constraints epec the outcome of the epec problem is a set of nash equilibria to tackle the multiple nash equilibria problem the concept of the extremal nash equilibria is defined and formulated we model the concept of extremal nash equilibria as a single stage mixed integer linear programming problem milp and demonstrate the application of this mathematical framework on an illustrative case and on a more realistic case study with tractable results

what makes a new business start up successful this paper seeks a good measure of new business performance and then explains this measure by various dimensions of business strategy three criteria are used to create a one dimensional ordinal ranking of high medium and low performance for new business starts employment growth return on capital employed and labour productivity it is shown that statistical cluster analysis provides a convincing separation of a sample of new business starts into high medium and low performance categories using a minimum distance criterion for clustering an ordinal logit model with selection is then used to explain this performance ranking the results indicate that many widely discussed features of small business strategy have little or even negative impact on performance of the numerous aims that owner managers may adopt survival growth etc only one appears to have a major impact on performance the pursuit of the highest rate of return on investment many entrepreneurial perceptions of their own capabilities appear false or unimportant with the exception of organisational features and systems

jobs off the farm wealth human capital and social group in rural eastern india abstractthis study examines the effects of wealth human capital and social group on the occupational choice and income of farm households to gain an understanding of the mechanism underlying the

security constrained unit commitment for simultaneous clearing of energy and ancillary services markets this paper introduces a security constrained unit commitment scuc model with emphases on the simultaneous optimization of energy and ancillary services markets benders decomposition is used to decouple the scuc into a unit commitment uc master problem and hourly network security checking subproblems lagrangian relaxation is used to decouple the uc problem into individual single unit commitment problems dynamic programming is used to find the optimal commitment decision a simultaneous marginal curve algorithm is proposed to find the optimal values of energy and ancillary services a six bus system with three units and the ieee 118 bus system with 54 units are analyzed to illustrate the proposed model

a cooperative multi area optimization with renewable generation and storage devices with the rising number of intermittent renewable energy sources and growing energy demand transfer capabilities are very close to their limits consequently redispatch events occur more frequently and flexibility of conventional generation and storage devices will become increasingly important the cooperative multi area optimization strategy presented here enables transmission system operators tsos to dispatch redispatch interconnected networks securely while reducing dispatch redispatch costs schedules for storage devices conventional and renewable generation are obtained considering network constraints and ramping rates an optimal schedule for several control areas is attained including storage operation to achieve congestion relief the distributed approach preserves control area responsibilities all participating control areas attain a schedule close to the global optimum tsos implement agreements to share resulting profits the functionality was shown successfully using stressed 14 and 118 node systems a cross border dispatch with use of storage devices is realized to maintain a high share of renewable energy source res feed in while reducing overall dispatch costs

personal networks and nonagricultural employment the case of a farming village in the philippines abstract this article based on an intensive village survey in the philippines analyzes the effects of personal networks on rural villagers access to nonagricultural occupations and the terms of employment given to them a key finding is that personal networks are selectively used to reduce transaction costs and their impacts on employment conditions vary by size and by location of enterprises we find that when villagers are employed in unskilled work at small enterprises those who use family relative networks receive wage premiums however if we limit our sample to small enterprises located near our study village the family relative network premiums become insignificant presumably because of the overriding influence of the community wide network within a narrow local community contrary to the case of small enterprises unskilled workers wages at large enterprises are not much affected by personal networks but are largely determined by years of schooling and work experience the recent developmen

schooling and earnings distributions with endogenous labour force participation marital status and family size this paper investigates the impact of various schooling investment strategies on family and per capita earnings within a framework that integrates effects on earnings family size marital status and labour force participation data are from a 1977 1978 survey of urban nicaraguan women aged 15 45 excerpt

optimal strategies for multiple participants in electricity markets this letter presents the solution framework for calculating multi participant nash equilibria in a transmission constrained electricity market the proposed framework which is generally applicable to various gaming conditions in electricity markets is used here for non cooperative complete information game between market participants with discrete bidding strategies the example in this letter shows the effectiveness of the proposed framework in finding the nash equilibrium

do more heavily regulated economies have poorer performing new ventures evidence from britain and spain we test two alternative perspectives on the start up size and subsequent growth of new firms in a heavily regulated hr economy and a lightly regulated lr economy the first argues that in an hr economy there will be fewer new firms and those that do start will be larger than those in an lr economy but they will grow more slowly a second perspective is that regulation does not influence the scale of entrepreneurship merely its distribution between that which is registered and that which is not registered using parallel datasets for hr spain and lr britain we find some support for both perspectives specifically we find that registered new firms in britain do start smaller than in spain and do grow faster however when both registered and unregistered firms are included these differences disappear

security constrained optimal coordination of generation and transmission maintenance outage scheduling the proposed approach to the optimal coordination of midterm planning can be used by vertically integrated utilities as well as the isos in electricity markets the approach coordinates the optimal maintenance scheduling of generating units and transmission lines within the outage scheduling horizon of weeks to months with the security constrained unit commitment of available components the proposed model provides hourly schedules for maintenance outages generation unit commitment and transmission flows based on hourly load curves in addition the approach calculates the optimal allocation of fuel and emission allowance for thermal units in a vertically integrated utility and energy allocation in electricity markets this paper discusses that a seamless coordination of midterm and short term optimization schemes will effectively improve the security of electricity services and reduce the chance of blackouts in aging power systems the proposed approach highlights a trade off between calculation speed and accuracy for large scale implementations a six bus system is used for detailed analyses and further results presented for the ieee 118 system exhibit the effectiveness of the proposed midterm planning approach