are we risking too much perspectives on risk in farm modelling risk and uncertainty have been extensively studied by agricultural economists in this paper we question a the predominant use of static frameworks to formally analyse risk b the predominant focus on risk aversion as the motivation for considering risk and c the notion that explicitly probabilistic models are likely to be helpful to farmers in their decision making we pose the question for a risk averse farmer what is the extra value of a recommendation derived from a model that represents risk aversion compared to a model based on risk neutrality the conclusion reached is that for the types of the decision problems most commonly modelled by agricultural economists the extra value of representing risk aversion is commonly very little

labor supply at the extensive and intensive margins the eitc welfare and hours worked some previous studies have emphasized differences between labor supply responses on the extensive margin participation and intensive margin hours worked e g james j heckman 1993 jean kimmel and thomas j kniesner 1998 recent tax and welfare policy changes provide a potentially more convincing way of identifying these responses than is available in other nonexperimental data the earned income tax credit eitc changes during the 1990 1996 period sharply altered the budget sets of single mothers over a short period of time these changes in incentives are likely to be unrelated to differences across individuals in the desire to work and thus are likely to be exogenous to labor supply decisions this lack of exogeneity is harder to claim for wage differences across people which are the main alternative source of identifying variation in addition to preference heterogeneity wages are driven by supply and demand factors that one must account for to obtain valid estimates using wage variation the eitc unequivocally encourages single parents to work at least some hours during a year because it shifts out the budget set at all positive hours points this first prediction is clearly confirmed by the data in addition theory implies that the eitc will decrease hours worked among those already working because most recipients are on the plateau or phase out portions of the credit schedule for these recipients the eitc reduces or does not affect the after tax wage while at the same time discouraging work through the income effect of the credit payment however recent hours worked patterns for eitc eligible individuals do not appear to fit this second prediction hours and weeks worked by likely recipient groups have not fallen this paper analyzes this puzzling finding building on earlier work by nada eissa and jeffrey liebman 1996 and meyer and dan t rosenbaum 1999 this study shows that nearly all of the laborsupply adjustment of single mothers occurs at the extensive margin not the intensive margin this finding raises the issue of what model features are needed to explain both participation and hours but leaves the answer to be provided in future work this finding also suggests that the large literature simulating alternative policies for low wage workers such as the eitc may be misleading because nearly all work has used models that imply similar responses on participation and hours margins

child care policy and the labor supply of mothers with young children a natural experiment from canada in 1997 the provincial government of quebec the second most populous province in canada initiated a new child care policy licensed child care service providers began offering day care spaces at the reduced fee of 5 00 per day per child for children aged 4 by 2000 the policy applied to all children not in kindergarten using annual data 1993 2002 drawn from statistics canada s survey of labour and income dynamics the results show that the policy had a large and statistically significant impact on the labor supply of mothers with preschool children

labour supply of married women in canada 1980 this study uses recently released data from the 1981 census to reex amine the labor supply behavior of married women in canada using j j heckman s procedure to correct for selectivity bias and incorporating the influence of income taxes this study finds small wage and income effects on canadian wives labor supply the estimat es are similar in magnitude to those reported by a n akamura and m nakamura 1981 in their study of data from the 1971 census and t o t he estimates reported in a more recent canadian study by c robinson and n tomes 1985 who used data drawn from the 1979 quality of life survey

marriage cohabitation and women s response to changes in the male wage structure using microdata and grouped data that cover the period 1996 to 2006 we assess the extent to which cohabiting women adjust their labour supply to a lesser extent if any than married women in response to changes in male wages both microdata regressions and grouping estimators unambiguously indicate that cohabiting women respond less to variation in male wages than married women however the magnitude of the difference is not sizeable we also assess the magnitude of married men s and cohabiting men s own wage elasticities and find that they do not differ much combined with the fact that male earnings account for roughly two thirds of family earnings these two findings explain why the impact of changes in male wages on family earnings is very similar for married couples and cohabiting couples in both cases a 10 decline in male wages appears to induce roughly a 6 drop in family earnings

the evolution of high incomes in northern america lessons from canadian evidence this paper uses tax statistics to construct new series on canadian top income shares from 1920 to 2000 and provides a systematic comparison with the u s experience as in the united states top income shares in canada display a ushaped pattern over the century with a precipitous drop during world war ii followed by a slower decline until 1970 since the late 1970s top income shares have been increasing dramatically and the very top shares are now as high as in the pre war era as in the united states the recent increase in top income shares is the consequence of a surge in top wages and salaries the canadian experience since the late 1970s does not appear to be well explained by tax changes suggesting that the upward trend in canada derives from the united states perhaps because many high income canadians have an emigration option this in turn suggests that the recent increase in u s personal income top shares is not merely a change in tax reporting behavior the recent sharp increase in top income shares in canada is of the same magnitude at the individual and family level and is not due to an increase in income mobility

methods for selecting the optimal dynamic hedge when production is stochastic a dynamic hedging problem with stochastic production is solved the optimal feedback rules recognize that future hedges will be chosen optimally based on the most current information the resulting distribution of revenue is analyzed numerically this analysis enables the hedger to select his appropriate level of risk aversion

how might china achieve its 2020 emissions target a scenario analysis of energy consumption and co2 emissions using the system dynamics model abstract according to the chinese government s co 2 reduction commitment the production and consumption of traditional and renewable energy in china from 2001 to 2012 this paper forecasts the energy consumption gross co 2 emissions and co 2 emission intensity in china from 2013 to 2020 via system dynamics simulation coupled with the energy system and renewable energy policy factors the effects of different economic growth rates and policy factors on the energy consumption were estimated the results showed that in different economic growth rates scenarios total energy consumption and co 2 emissions increased by 36 140 75 kwh and more than 10 000 billion kg in 10 gdp growth rate scenario than in the 7 scenario in 2020 the co 2 emission per gdp decreased by 52 in 2020 as compared to 2005 under the scenario of 10 gdp growth rate under different renewable energy policy factors scenarios the coal energy consumption decreased by 2 3 in scenario of 5 policy factor as compared to 1 policy factor scenario the co 2 emissions reduced by 3321 94 billion kg in 2020 under the scenario of 5 policy factor as compared to that in the scenario of 1 policy factor the co 2 emission per gdp reduced by 47 50 based on the 2005 level in different scenarios of renewable energy policies we found that with an increase in gdp total energy consumption and co 2 emissions increased in the base scenario higher economic growth rates led to an increase in energy consumption including both the traditional and renewable energy resources in stark contrast to total co 2 emission however co 2 emission intensity decreased with an increase in economic growth rate the renewable energy policy improved the renewable energy development reduced co 2 emissions and co 2 emission intensity it was more effective in energy saving and co 2 reduction than the high growth rate scenarios the results indicated that china is highly likely to achieve its co 2 emission reduction goal under different simulated scenarios besides the energy distribution was similar in different scenarios coal was the major energy source which amounted to more than 70 of the total energy consumption finally we conclude with important policy implications according to our simulations results

are women s wage gains men s losses a distributional test department of economics university of british columbia vancouver bc v6t 1z1 and department of economics crde cirano universite de montreal montreal pq h3c 3j7 lemieux is also affiliated with the nber we thank paul beaudry richard blundell richard freeman and robert haveman for helpful comments and discussions we gratefully acknowledge financial support from the social sciences and humanities council of canada and from fcar quebec 1 the gender wage ratio and the 90 50 wage ratio for men are calculated from the current population survey cps data provided by epi http www epinet org the 1980 s trends in the gender gap emerged from average real increases of 0 5 percent per year in women s median wages and average real declines of 1 percent per year in men s median wages

what has been learned about labor supply in the past twenty years the main advance in the study of labor supply in the past 20 years has come in recognizing and interpreting the variety of different labor supply functions that coexist in the empirical literature a crucial theoretical distinction with important empirical payoff is that between labor supply choices at the extensive margin i e labor force participation and employment choices and choices at the intensive margin i e choices about hours of work or weeks of work for workers another important distinction is the one between a descriptive labor supply function and a structural supply function that can be the basis for out of sample policy investigations concerning responses to tax and welfare programs and evaluations of welfare losses a full understanding of the participation hours dichotomy leads to an appreciation of the importance of the problem of selection bias what is the wage to impute to a nonworking person these distinctions are a legacy of the research conducted on labor supply over the past 20 years many important empirical questions have been addressed i how strong are the effects of taxes welfare and transfer programs on labor supply ii how important is intertemporal substitution can life cycle labor supply models explain business cycle labor supply behavior iii has the consensus view of the 1960 s of high labor supply elasticities for married women and low labor supply elasticities for married men held up all of the empirical evidence assembled on labor supply must be called into question in the light of important research on the basic quality of the data conducted by analysts at the university of michigan i discuss this evidence in a concluding section except for my discussion of measurement issues i focus only on the major discoveries about which a general consensus has emerged

estimating labour supply responses using tax reforms the 1980 s tax reforms and the changing dispersion of wages offer one of the best opportunities yet to estimate labor supply effects nevertheless changing sample composition aggregate shocks the changing composition of the tax paying population and discontinuities in the tax system create serious identification and estimation problems we develop grouping estimators that address these issues our results reveal positive and moderately sized wage elasticities we also find negative income effects for women with children

changes in the labor supply behavior of married women 1980 2000 using march current population survey data we investigate married women s labor supply from 1980 to 2000 we find a large rightward shift in their labor supply function for annual hours in the 1980s with little shift in the 1990s these shifts account for most of the slowdown in the growth of labor supply during this period a major development was the dramatic decrease in the responsiveness of married women s labor supply to their own and husbands wages their own wage elasticity fell by 50 56 while their cross wage elasticity fell by 38 47 in absolute value

the market work behavior and wages of women 1975 94 changes in the labor market participation and wages of women in the united states are analyzed over the period 1975 1994 using data from the current population survey women are organized into nine birth cohorts five schooling groups and each year of age from 25 to 60 years and their weekly and annual work hours their annual work weeks their employment population ratio and their real average hourly earnings tabulated schooling differences in work behavior have become wider in recent cohorts as have their wages the relationship between work and wages is estimated for women of different ages cohorts and marital status the gap between the work of unmarried and married women has narrowed and the role of wages both the wages of women and those of husbands is examined to determine the extent to which changes in wages account for these movements excerpt

the impact of child care costs on the labour supply of married mothers evidence from canada this paper provides estimates for canada of the impact of childcare costs on the labor supply of married mothers this is done by linking two microdata sources the 1988 canadian national child care survey and the 1988 labour market activity survey the key results show that the market wage and childcare costs have respectively a significant positive and negative impact on both hours of work and the labor force participation decision by married mothers the childcare cost elasticities for labor force participation and hours of work are reported to be 0 38 and 0 32 respectively

assortative mating and female labor supply this paper investigates married women s hours worked disaggregated by the husband s wage decile in the united states this pattern has changed from downward sloping to hump shaped we show that this development can be explained within a standard household model of labor supply when taking into account trends in assortative mating a quantitative analysis of our model shows that female wage growth and decreasing fertility are primarily responsible for the overall increase in wives hours since the 1970s the fact that the most pronounced increases are observed for wives married to high wage men is a result of trends in assortative mating

joint labor supply and childcare choice decisions of married mothers this paper examines the impact of childcare prices and wage rates on the joint employment and childcare mode center sitter relative and husband choice decisions of married mothers by estimating both a mixed logit and universal logit choice model data are drawn from the 1988 canadian national child care survey and the 1988 labour market activity survey the estimation results show that wages have a positive impact on the probability of choosing any of the working states and that childcare prices for center sitter and relative care reduce the probability of working and using each respective mode of care sensitivity analyses reveal that the wage elasticity for employment is fairly robust across model specifications while the own price elasticity of childcare is sensitive to model specification differing identifying assumptions in the estimation of childcare price equations and sample selection the simulation results show that differences exist in the degree to which government subsidies in the form of wage subsidies targeted childcare subsidies or unconditional childcare subsidies impact on labor supply decisions and decisions to substitute across different modes of care by those mothers already in the labor market

small sample bias in synthetic cohort models of labor supply this paper investigates small sample biases in synthetic cohort models repeated cross sectional data grouped at the cohort and year level in the context of a female labor supply model i use the current population survey to compare estimates when group sizes are extremely large to those that arise from randomly drawing subsamples of observations from the large groups i augment this approach with monte carlo analysis so as to precisely quantify biases and coverage rates in this particular application thousands of observations per group are required before small sample issues can be ignored in estimation and sampling error leads to large downward biases in the estimated income elasticity copyright 2007 john wiley sons ltd

does the labour supply of wives respond to husbands wages canadian evidence from micro data and grouped data using micro data and grouped data we assess the extent to which canadian wives adjusted their labour supply in response to changes in husbands wages during the period 1980 2000 grouped data parameters based on weighted least squares and the unbiased error in variables estimator developed by devereux 2004 2007a b yield cross wage elasticities that are substantially higher in absolute value than those derived from ols regressions run on micro data both grouping estimators indicate that the labour supply of canadian wives responded strongly to changes in husbands wages during the 1980s for the 1990s our estimates of wives cross wage elasticity display greater dispersion a l aide de micro donnees et de donnees groupees on etablit jusqu a quel point les epouses canadiennes ont ajuste leur offre de travail en reponse aux changements dans les salaires de leurs epoux au cours de la periode 1980 2000 les parametres pour les donnees groupees derives par la methode des moindres carres ponderes et de l estimateur developpe par devereux 2004 2007a b engendrent des elasticites croisees qui sont substantiellement plus grandes en termes absolus que ceux derives par la methode des moindres carres ordinaires en utilisant des micro donnees les deux estimations montrent que l offre de travail des epouses canadiennes a repondu fortement aux changements dans les salaires des epoux au cours des annees 80 pour les annees 90 les evaluations des elasticites croisees des salaires montrent une plus grande dispersion

behavioural response to ui reform in constrained and unconstrained models of labour supply this paper investigates how taking account of demand side constraints affects estimated models of labor supply and hence predicted behavioral responses to unemployment insurance reform in canada constrained and unconstrained labor supply equations are estimated for single men and women using microdata from the 1982 survey of consumer finance detailed modeling of the impact of the canadian unemployment insurance program on individual budget constraints enables the simulation of behavioral responses to the unemployment insurance reform proposals of the forget and macdonald commissions results indicate that in a high unemployment economy labor supply responses will be negligible

family labour supply and fertility a two regime model the central hypothesis of the new micro economics of fertility was examined i e because children are female time intensive fertility is inversely related to the mothers wage a theoretical model of lifetime family labor supply and completed fertility which forms the basis for the subsequent empirical investigation is presented empirical estimates of the model are provided using 1971 canadian census data the 1 period model of completed family size and lifetime labor supply indicates that fertility and labor supply behavior of families where the wife participates in the labor market will differ from that of families with never participating wives the systematic differences arise because families with nonworking wives face the additional binding constraint of an inflexible supply of wifes time to the home a comparison of these 2 regimes allows inferences concerning the female time intensity of children and the substitutability of husbands and wifes time in the context of the 1 period model the relevant criterion for separating families into the 2 regimes is the lifetime rather than current participation status the evidence suggests that when this procedure is followed much doubt is cast on the conventional wisdom that children are female time intensive the usual inverse relation found between wifes wage or education and completed family size appears to be the result of a complex interaction between wage rates lifetime labor force participation and fertility some support is found for complementarity between the home time of the husband and wife but the evidence is not totally consistent results of the female participation equation strongly suggest complementarity proxies for the husbands lifetime labor supply suggest weak or zero complementarity when the sample is split by current participation of the wife rather than lifetime participation then the results support conventional wisdom concerning the female time intensity of children and replicate kneisners finding of complementarity between husband and wifes time reconciling these differences within the framework of the 1 period model is difficult since it yields no predictions concerning current variables yet since the wifes lifetime participation is the correct criterion for allocating families to the 2 regimes under the 1 period model doubt must remain concerning the female time intensity of children until the current lifetime results are reconciled

a comparison of the labor force behavior of married women in the united states and canada with special attention to the impact of income taxes estimation results are presented for the probability of working the hourly wage rate and the annual hours of work for wives in seven different age groups in both the u s and canada federal and state or provincial taxes are incorporated into the analysis an iterative estimation method is employed to circumvent the statistical problems resulting from the dependence of the hours of work on the tax rate and the dependence of the tax rate on the hours of work authors

canadian contributions to family economics canadian scholars have made substantial contributions to the relatively new field of family economics these include new models of how men and women match in marriage markets and of how decisions are made in multi person households several were early contributors to the literature on married women s labour supply and labour supply in a family context and helped to develop empirical methods in this area a particular focus has been on the impacts of policy relevant parameters such childcare costs on family labour supply and child well being new work on child development the impact of early life conditions and the processes of intergenerational transmission also highlight the importance of family context in determining economic well being

eroi of different fuels and the implications for society abstract all forms of economic production and exchange involve the use of energy directly and in the transformation of materials until recently cheap and seemingly limitless fossil energy has allowed most of society to ignore the importance of contributions to the economic process from the biophysical world as well as the potential limits to growth this paper centers on assessing the energy costs of modern day society and its relation to gdp our most important focus is the characteristics of our major energy sources including each fuel s energy return on investment eroi the eroi of our most important fuels is declining and most renewable and non conventional energy alternatives have substantially lower eroi values than traditional conventional fossil fuels at the societal level declining eroi means that an increasing proportion of energy output and economic activity must be diverted to attaining the energy needed to run an economy leaving less discretionary funds available for non essential purchases which often drive growth the declining eroi of traditional fossil fuel energy sources and the effect of that on the world economy are likely to result in a myriad of consequences most of which will not be perceived as good

wage inequality and family labor supply using the march current population surveys and the 1960 census this article describes earnings and employment changes for married couples in different types of households stratified by the husband s hourly wage while declines in male employment and earnings have been greatest for low wage men employment and earnings gains have been largest for wives of middle and high wage men these findings cast doubt on the notion that married women have increased their labor supply in the recent decades to compensate for the disappointing earnings growth of their husbands

child care costs and the employment decision of women canadian evidence the authors estimate the joint decision for women with preschool children to engage in paid employment and to purchase market forms of child care the results confirm those found in most u s studies indicating that child care costs exert a significant negative effect on the labor supply of women with children and on their decision to purchase child care as well the expected wage of the mother exerts a significant positive impact on both the decision to purchase market forms of child care and the decision to engage in paid unemployment

multi dimensional pinch analysis for sustainable power generation sector planning in china emerging economies account for a fast growing share of the global energy market in particular energy use in china has become significant from both economic and environmental standpoints this trend makes it necessary to balance the need for affordable reliable electricity supply with the need to ensure that the power infrastructure is environmentally sustainable as such this paper presents a multi dimensional pinch analysis mdpa of the power generation sector in china the analysis considers five key indices carbon footprint energy return on investment eroi water footprint land footprint and risk to humans by simultaneously quantifying five different indices under a common methodological framework we are able to coherently assess the impact on five different environmental concerns this approach provides a more complete picture of the true environmental impact of china s power sector this information can thus help policymakers avoid the problem of shifting environmental impacts to other domains which can occur when the analytic procedure used focuses on a single environmental dimension

single women s labor supply elasticities trends and policy implications this paper uses cps data to examine changes in single women s labor supply elas ticities in recent decades specifically the authors investigate trends in how single women s hours of work and labor force participation rates responded to both wages and income over the years 1979 2003 results from the base specification suggest that over the observation period hours wage elasticities decreased by 82 participation wage elasticities by 36 and participation income elasticities by 57 these results imply that changes in tax policy had a much larger effect on the labor supply and labor force participation behavior of women in this subpopulation in the early 1980s than in recent years i t is well documented that over the past few decades female labor force behavior has undergone substantial changes women s labor force participation rates have increased markedly as have their annual hours of work at the same time the marital composition of women has undergone a substantial change as well with the proportion of married women falling steadily over time as a result single women comprise a greater share of the labor force than in earlier years and hence their behavioral responses to changes in wages and incomes carry even greater importance for the effects of changes in tax and transfer policies despite the large increase in the number of single women over the past decades single women s labor supply behavior has received

national family policies and mothers employment how earnings inequality shapes policy effects across and within countries although researchers generally agree that national family policies play a role in shaping mothers employment there is considerable debate about whether how and why policy effects vary across co

changes in relative wages and family labor supply the large changes in relative wages that occurred during the 1980s provide fertile ground for studying the behavioral responses of married couples to the wage changes of husbands and wives i find estimates of own wage and cross wage elasticities for men that are very small the own wage elasticity for women is positive and the cross wage elasticity for women suggests a strong negative response of female labor supply to changes in their husband s wages family labor supply behavior determines how changes in individual wage rates translate into family earnings changes the responses of women to changes in their husband s wages attenuated somewhat the increases in individual wage inequality at the family level the results suggest that the earnings of the wives of low income men would actually have fallen over the decade if women s labor supply did not respond to changes in their husbands wages however assortative mating implies that wage changes of husbands and wives are correlated and so family earnings inequality still grew during the decade of the 1980s

the incredible shrinking elasticities married female labor supply 1978 2002 this paper demonstrates the extent to which married women s labor supply elasticities have changed over the past quarter century estimates from march current population survey data suggest that these elasticities have decreased substantially by 60 percent for the hours wage elasticity from 0 36 to 0 14 70 percent for the hours income elasticity from 0 053 to 0 015 95 percent for the participation wage elasticity from 0 66 to 0 03 and 60 percent for the participation income elasticity from 0 13 to 0 05 changing demographic characteristics explain little of the drop in these elasticities suggesting that preferences toward work have changed across birth cohorts

employment and child care choices in canada and the united states in this paper we examine employment and child care choices of two parent families with young children in the united states and canada using a pooled data set based on recent national surveys in each country we find that the employment and child care choices of canadian families are similar to those of u s families estimates of a model of employment and child care choices indicate significant effects of child care subsidies child care prices and wage rates on employment and child care choices however none of these factors helps to explain the differences in employment and child care choices between the two countries ce memoire examine le choix de l emploi et du soin des enfants dans les familles ou il y deux parents aux etats unis et au canada en utilisant des donnees d etudes recentes dans les deux pays il appert que les choix des familles canadiennes sont semblables a ceux des familles americaines les calibrations d un modele de ces choix montrent les effets significatifs des subventions au soin des enfants du prix des soins des enfants et des taux de salaires sur ces choix cependant aucun de ces facteurs n explique les diffrences dans les patterns de choix entre les deux pays

more on the labour supply of canadian women the traditional consensus on female labour supply is that the wage elasticity is large and positive in contrast to a small and generally negative elasticity for males this consensus has recently been challenged in a series of important papers by alice and masao nakamura who find a backward bending supply curve for females similar to that for males this result has been challenged on a variety of grounds the present paper tests the hypothesis advanced by the nakamuras on data that have several advantages over the census type in their papers the results offer strong support for the nakamuras conclusions

new estimates of labour supply elasticities for married women in canada 1996 2005 in this article we estimate income and substitution labour supply and participation elasticities for canadian married women using data from the survey of labour and income dynamics 1996 2005 we use the canadian tax and credit simulator ctacs and detailed information on the structure of income at the household level to compute the marginal tax rates faced by each individual we then use these marginal tax rates to compute net own wage spouse wage and nonlabour income we show how the magnitude of the estimated elasticities varies depending on whether net or gross wages and income are used in the estimation procedure and quantify biases caused by using average tax rates instead of marginal tax rates finally because marginal tax rates vary significantly over the sample we use quantile regressions to compare elasticities at different points of the hours distribution overall our results show that public policies now have on average less scope for influencing hours of work than 10 years ago howev

factor proportions and relative wages the supply side determinants of wage inequality supply side factors may contribute to rising wage inequality first certain changes in the supply of skills allegedly exacerbate wage inequality women s increased labor force participation and increased immigration are the leading candidates both allegedly reduce the wages of less skilled men however immigration s impact on wage inequality has been minor and the effects of women s participation is inconclusive second in evaluating the likelihood that human capital investment will mitigate future inequality evidence suggests that rising returns to education have increased the proportion of young people attending college limiting the growth of inequality among high wage workers

dynamic marketing and retention decisions for cow calf producers optimal calf retention and marketing activities for cow calf producers are examined using a expected utility maximizing discrete stochastic programming model steer heifer and corn prices are modeled as stochastic variables the mathematical model is used to consider retention at weaning and yearling stages and marketing alternatives of cash hedging and options results show how calf retention decisions depend upon current profit expected future profit distributions pricing alternatives available and the cow calf producer s aversion to risk

swimming upstream trends in the gender wage differential in the 1980s using michigan panel study of income dynamics data for 1979 and 1988 we analyze how a falling gender wage gap occurred despite changes in wage structure unfavorable to low wage workers the decrease is traced to gender specific factors which more than counterbalanced changes in measured and unmeasured prices working against women supply shifts net of demand were unfavorable for women generally and hurt high skilled more than middle and low skilled women by analyzing wages we find support for the notion of a gender twist in supply and demand having its largest negative effect on high skilled women