short term optimal wind power generation capacity in liberalized electricity markets mainly because of environmental concerns and fuel price uncertainties considerable amounts of wind based generation capacity are being added to some deregulated power systems the rapid wind development registered in some countries has essentially been driven by strong subsidizing programs since wind investments are commonly isolated from market signals installed wind capacity can be higher than optimal leading to distortions of the power prices with a consequent loss of social welfare in this work the influence of wind generation on power prices in the framework of a liberalized electricity market has been assessed by means of stochastic simulation techniques the developed methodology allows investigating the maximal wind capacity that would be profitably deployed if wind investments were subject to market conditions only for this purpose stochastic variables determining power prices are accurately modeled a test system resembling the size and characteristics of the german power system has been selected for this study the expected value of the optimal short term wind capacity is evaluated for a considerable number of random realizations of power prices the impact of dispersing the wind capacity over statistical independent wind sites has also been evaluated the simulation results reveal that fuel prices installation and financing costs of wind investments are very influential parameters on the maximal wind capacity that might be accommodated in a market based manner

the effects of human resource management practices on productivity a study of steel finishing lines the authors investigate the productivity effects of innovative employment practices using data from a sample of thirty six homogeneous steel production lines owned by seventeen companies the productivity regressions demonstrate that lines using a set of innovative work practices which include incentive pay teams flexible job assignments employment security and training achieve substantially higher levels of productivity than do lines with the more traditional approach which includes narrow job definitions strict work rules and hourly pay with close supervision their results are consistent with recent theoretical models which stress the importance of complementarities among work practices

do international students crowd out or cross subsidize americans in higher education abstract recent growth in international enrollment at u s universities has raised controversy while critics accuse international students of displacing american students university administrators have argued that they provide much needed tuition revenue this paper examines how international students impact domestic enrollment focusing on a unique boom and bust in international matriculation into u s graduate programs from 1995 to 2005 overall foreign students appear to increase domestic enrollment this positive effect is linked to cross subsidization whereby high net tuition payments from foreign students help subsidize the cost of enrolling additional domestic students

emigration and wages in source countries evidence from mexico abstract this paper examines empirically the effect of mexican emigration to the united states on wages in mexico using data from the mexican and us censuses from 1970 to 2000 the main result in the paper is that emigration has a strong and positive effect on mexican wages there is also evidence for increasing wage inequality in mexico due to emigration simple welfare calculations based on a labor demand supply framework suggest that the aggregate welfare loss to mexico due to emigration is small however there is a significant distributional impact between labor and other factors

retailers as agents and the limits of parallel trade abstract the volume of retail level parallel trade is surprisingly small despite persistent international price differences we offer an agency based explanation by considering competition between an original home manufacturer and a foreign retailer the model endogenizes the role of the retailer as an agent with private information on the perceived quality of the good in its own market the manufacturer cannot control the retailer once the latter has ordered its sales quantity but it can limit the initial offer if parallel trade is permitted this offer will fall if there is incomplete information resulting in a small or zero volume of parallel trade this outcome makes both the original producer and foreign consumers worse off while offering little benefit to home consumers compared to the case where such trade is banned

the impact of permanent residency delays for stem phds who leaves and why abstract this paper assesses whether delays in obtaining permanent residency status can explain recent declines in the share of chinese and indian phd graduates from us stem programs who remain in the us after their studies we find that newly binding limits on permanent visas for those from china and india with advanced degrees are significantly associated with declines in stay rates the stay rate of chinese graduates declines by 2 1 percentage points for each year of delay while indian graduates facing delays of at least 5 years have a stay rate that is 10 6 percentage points lower the per country permanent visa cap affects a large share of stem phds who are disproportionately found in fields of study that have been crucial in stimulating us economic growth yet enroll relatively few natives finally results suggest that the growth of science in countries of origin has an important influence on stay rates while macroeconomic factors such as gdp per capita affect stay rates only via their impact on science funding we conclude that per country limits play a significant role in constraining the supply of highly skilled stem workers in the us economy

skilled immigration and innovation evidence from enrolment fluctuations in us doctoral programmes we study the contribution of foreign science and engineering talent to the creation of new knowledge in the u s economy using panel data on 2300 science and engineering s e departments at 100 large american universities from 1973 to 1998 we use macroeconomic shocks and policy changes in source countries that differentially affect enrollments across fields and universities to isolate exogenous variation in the supply of students at specific departments both foreign and domestic graduate students are central inputs into knowledge creation and the marginal foreign student contributes more to the production of scientific publications and citations a 10 decrease in the foreign share of doctoral students lowers s e research output at u s universities by 5 6 a theoretical model of university admissions and scholarships helps us infer the productivity effects of student quality and econometric results indicate that any visa restrictions limiting entry of highquality foreign students is most costly for u s innovation increased diversity appears to be the primary mechanism by which foreign students improve research outcomes the impact of more restrictive immigration policies depends on how they affect the quality margin and diversity of incoming foreigners

the cost structure of american research universities 1597 this study estimates translog variable cost functions for 147 american doctorate granting universities accounting for three major products of these institutions undergraduate and graduate instruction and research explicit measures of research output and quality are employed evidence is found for considerable economies of scale for the average institution as well as economies of scope related to the joint production of undergraduate and graduate instruction the public or private ownership of an institution is not significant for the explanation of variable costs the intensity of state regulation in the public sector does not have a significant impact on production efficiency copyright 1991 by mit press

efficient pricing and investment in electricity markets with intermittent resources facing growing technological and environmental challenges the electricity industry needs effective pricing mechanism to promote efficient risk management and investment decisions in a restructured electricity market with competitive wholesale prices and traditionally regulated retail rates however there are technical and institutional barriers that prevent dynamic pricing with price responsive demand in regions with limited energy storage capacity intermittent renewable resources present special challenges this could adversely affect the effectiveness of public policies causing inefficient investments in energy technologies in this paper we present an updated economic model of pricing and investment in restructured electricity market and use the model in a simulation study for an initial assessment of renewable energy strategy and alternative pricing mechanisms a key objective of the study is to shed light on the policy issues so that effective decisions can be made to improve efficiency

undocumented immigration and unemployment of u s youth and minority workers econometric evidence we use census based data on the state distribution of the undocumented alien population in analyzing the relationship between that population and unemployment among youth and minority workers in the united states regression results from our two equation models do not support commonly expressed fears that undocumented immigration has caused any substantial increases in joblessness among these presumably vulnerable groups although small amounts of displacement are indicated a sizeable reverse effect is evident undocumented immigrants tend to concentrate in states where labor markets for these marginal groups are most favorable excerpt

regional labor markets and the determinants of wage inequality from 1972 to 1990 the united states experienced the largest increase in wage inequality of any developed country the spread in log wages between the 90th and 10th percentiles of the male wage distribution increased by about 60 points and inequality increased within virtually every demographic or skill category of the labor force see chinhui juhn et al 1993 various explanations have been offered including changes in the relative demand for skill intensive goods international trade immigration of less skilled workers and increased labor force participation of women yet attempts to quantify the relative importance of these factors have not met with much success this leaves skill biased technical change as the residual claimant that rationalizes the data this paper uses regional differences in the evolution of wage inequality to provide new evidence on the determinants of relative wages using a model of factor demand in geographic markets i isolate contributions of i changing skill ratios in the labor force ii increased participation of women iii technical change and iv changes in the industrial composition of labor demand the data indicate that changing skill ratios and women s labor supply have affected the wages of low skilled men in the west the data indicate that increased immigration of less skilled hispanic and asian workers has adversely affected the wages of natives causing a greater increase in inequality there than in any other region of the country i modeling wage inequality in regional markets

peers at work we study peer effects in the workplace specifically we investigate whether how and why the productivity of a worker depends on the productivity of coworkers in the same team using high frequency data on worker productivity from a large supermarket chain we find strong evidence of positive productiv ity spillovers from the introduction of highly productive personnel into a shift worker effort is positively related to the productivity of workers who see him but not workers who do not see him additionally workers respond more to the presence of coworkers with whom they frequently interact we conclude that social pressure can partially internalize free riding externalities that are built into many workplaces jel j24 l81 m54

regression toward mediocrity in economic stature this paper provides estimates of the correlation in lifetime earnings between fathers and sons intergenerational data from the national longitudinal survey are used earlier studies conducted for the united states report elasticities of children s earnings with respect to parent s earnings of 0 2 or less suggesting extensive integenerational mobility these estimates however are biased downward by error contaminated measures of lifetime economic status estimates presented in this paper correct for the problem of measurement error and find the intergenerational correlation in income to be on the order of 0 4 this suggests considerably less intergenerational mobility than previously believed jel j62

immigration from poor to wealthy countries experience of the united states the u s experience with immigration from poor countries is examined using the results of two projects carried out by the national bureau of economic research questions considered include what determines the supply of immigrants how such immigrants fare in the u s job market and how this immigration affects the prospects of native born workers annotation

intergenerational income mobility in the united states social scientists and policy analysts have long expressed concern about the extent of intergenerational income mobility in the united states but remarkably little empirical evidence is available the few existing estimates of the intergenerational correlation in income have been biased downward by measurement error unrepresentative samples or both new estimates based on intergenerational data from the panel study of income dynamics imply that the intergenerational correlation in long run income is at least 0 4 indicating dramatically less mobility than suggested by earlier research copyright 1992 by american economic association

assessing the advantages and drawbacks of government trading of guarantees of origin for renewable electricity in europe abstract the european commission has proposed a new renewable energy directive which includes flexibility provisions allowing the cost effective attainment of the ambitious target for renewable energy of 20 of energy consumption which has been set for the year 2020 one of the flexibility provisions currently being considered is to allow countries to reach their individual targets by buying their renewable electricity deployment deficit from other countries with a surplus i e with a renewable electricity deployment above their targets this trade is likely to take the form of an exchange in guarantees of origin gos gos are currently implemented in member states to fulfil the renewable electricity directive requirement that each country has a system that allows the tracing of the source of each kwh of renewable electricity and informs on this source although the recent and tiny literature on the analysis of go trading has focused on trade between firms the exchange of gos between governments has not received a comparable attention this paper analyses the advantages and drawbacks of a system of government trading of gos with respect to company trading

economic curtailment of intermittent renewable energy sources abstract in a power system featuring a large share of intermittent renewables and inflexible thermal generators efficiency gains could be achieved by curtailing the production of renewables however as renewables feature very low variable production costs over curtailment can be costly in this article we use a stylised analytical model to assess this trade off we show that while curtailing renewables when their variability is high and the system flexibility is low can reduce generation costs the different stakeholders will not necessarily benefit from such measures as a consequence leaving this decision to generators will lead to a sub optimal level of curtailment either incentives to provide accurate res availability forecasts or alternatively centralised forecasting should be put into place to solve the resulting problem of asymmetry of information

the effect of immigration on innovation in italy abstractthis paper investigates the effect of immigration on innovation in italy a country characterized by prevalently unskilled immigration after addressing the potential endogeneity of the share of immigrants in the population using immigrant enclaves no evidence is found of either positive or negative effects of migrants on innovation this result is robust to allowing for different effects of low and medium high skilled migrants to using linear and non linear models and to considering both province level data on patent applications and firm level self reported measures also capturing innovation adoption

a capacity investment model of wind power with uncertain supply price under high penetration rate abstract with the rapid development of renewable energy the proportion of wind power in power supply has grown significantly also it influences the power price fluctuation since the marginal cost of wind power is almost zero the growth of wind power s penetration rate has led to a crowding out effect and challenged traditional power generation technology substantially reducing the power price in the market in perfect competition market the real time balance between supply and demand of power is regulated by the real time power price fluctuation so this paper models the intermittence of wind power as uncertain supply and develops a capacity investment model under the uncertainties of both supply and demand we introduce priority dispatch elasticity to describe the crowding out effect and take the power price to be endogenous in order to model the situation of high penetration rate we compare the optimal wind power capacity decision under the strategy of priority grid connection and abandoned power management our results show that optimal capacity investment is inversely related to priority dispatch elasticity under both strategies however the profit from power generation is always higher when adopting the abandoned power management strategy

the scale and selectivity of foreign born phd recipients in the us abstract we study the scale and selectivity of foreign born phd students in science and engineering we focus on students from china india korea and taiwan which together account for most rough

pros and cons of exposing renewables to electricity market risks a comparison of the market integration approaches in germany spain and the uk abstract the article examines how renewable electricity res e producers are integrated into the electricity market under the support legislations and regulatory frameworks of germany spain and the uk focus is on wind power which faces the highest market integration challenge of all res e the analysis shows that the three countries follow contrasting approaches of exposing res e producers to the market risks of forward electricity markets balancing markets and system planning requirements risk exposure is highest in the uk and lowest in germany from a policy maker s perspective there is a trade off between a high risk and a low risk approach when res e face high market risks a higher level of financial support is required to stimulate res e development than in a low risk environment but the exposure to market risks may also give an incentive to make efficient use of the respective market thus limiting the indirect costs to society the special characteristics of wind energy however put natural limits to the response of wind power plants to market prices and locational price signals and will increasingly influence electricity markets and grid infrastructure these interdependencies should be recognised in the design of res e policies and market regulations

the effect of low skilled immigration on u s prices evidence from cpi data i exploit the large variation across u s cities and through time in the relative size of the low skilled immigrant population to estimate the causal effect of immigration on prices of nontraded goods and services using an instrumental variables strategy i find that at current immigration levels a 10 percent increase in the share of low skilled immigrants in the labor force decreases the price of immigrant intensive services such as housekeeping and gardening by 2 percent wage equations suggest that lower wages are a likely channel through which these effects take place however wage effects are significantly larger for low skilled immigrants than for low skilled natives implying that the two are imperfect substitutes

assimilation changes in cohort quality and the earnings of immigrants this paper reexamines the empirical basis for two facts that seem to be found in most cross section studies of immigrant earnings 1 the earnings of immigrants grow rapidly as they assimilate into the united states and 2 this rapid growth leads to many immigrants overtaking the earnings of the natives within 10 15 years after immigration using the 1970 and 1980 u s censuses this paper studies the earnings growth experienced by specific immigrant cohorts during the period 1970 80 it is found that within cohort growth is significantly smaller than the growth predicted by cross section regressions for most immigrant groups this differential is consistent with the hypothesis that there has been a secular decline in the quality of immigrants admitted to the united states

labor market openness h 1b visa policy and the scale of international student enrollment in the united states international students have long comprised an important part of u s higher education however little is known regarding the factors that encourage students from across the world to enroll in u s colleges and universities each year this paper examines the relationship between international enrollment and the openness of the united states skilled labor market currently regulated by the h 1b program gravity regressions reveal that h 1b visa issuances to a country are positively and significantly related to the number of international students from that country causal estimates of the impact of labor market openness are achieved by exploiting a dramatic fall in the h 1b visa cap in october 2003 triple difference estimates show that the fall in the cap lowered foreign enrollment by 10 jel f22 i21 j11

global talent flows the global distribution of talent is highly skewed and the resources available to countries to develop and utilize their best and brightest vary substantially the migration of skilled workers across countries tilts the deck even further using newly available data the paper first reviews the landscape of global talent mobility which is both asymmetric and rising in importance next the determinants of global talent flows at the individual and firm levels are presented and some important implications are sketched third the national gatekeepers for skilled migration and broad differences in approaches used to select migrants for admission are reviewed looking forward the capacity of people firms and countries to successfully navigate this tangled web of global talent will be critical to their success

international migration under asymmetric information international migration under asymmetric information usually differs from international migration under symmetric information and often quite dramatically so and in counterintuitive ways since in real life information is indeed asymmetric it is somewhat surprising that hitherto the study of international migration has by and large proceeded without explicit recognition of the effect of informational asymmetry in this paper we show that when at the lowest skill level migration is desirable i e if the discounted wage differential is positive for the lowest skill level the introduction of asymmetric information results in a reduction of the quality and quantity of international migration or has no effect at all when at the lowest skill level migration is not desirable the discounted differential is not positive at the lowest skill level the introduction of asymmetric information may either result in migration by all or none when under asymmetric information workers can at some cost to themselves report to foreign employers their individual skill thus dissociate themselves from the group effect then provided the cost is small either a u pattern of migration with respect to skill level emerges or migration is uniformly pursued by all though some do and some do not invest in signalling when the source consists of more than 1 poor country it is impossible to predict migration under asymmetric information from a given country without explicitly accounting for changes in the parameters of the other for example a favorable change encouraging less migration taking place in 1 country will through a distinct impact on the overall composition of migration reduce migration from the other country finally allowing employers to discover after a while the true productivity of individual migrant workers we obtain the somewhat surprising result that under a reasonable set of assumptions eventual discovery may increase the quantity and quality of migration and also increase the wage enjoyed by the low quality migrants eventual discovery serves to mitigate the impact of group averaging that deters migration by the high skill workers due to migration of some such workers the prediscovery wage of the low skill workers arises in our case sufficiently to outweigh the effect of the future wage decline due to discovery authors

vertical distribution parallel trade and price divergence in integrated markets we develop a model of vertical pricing in which an original manufacturer sets wholesale prices in two markets that are integrated at the distributor level by parallel imports pi the manufacturing rm needs to set these two prices to balance three competing interests restricting competition in the pi recipient market avoiding resource wastes due to actual trade and reducing the double markup problem in the pi source nation

real indeterminacy with financial assets abstract it is shown that in a two period general equilibrium securities model where assets pay in money the generic dimension of the set of equilibrium allocations in the incomplete market situation is s 1 where s is the number of assets hence the degree or real indeterminacy is independent of the number of assets this result requires beyond fewer assets than states that the number of traders be larger than the number of securities and that the asset return matrix be in general position the generic dimension for arbitrary returns matrix is also obtained it is argued in addition that the presence of real or mixed assets does not by itself lower the degree of indeterminacy

harmonization of renewable electricity feed in laws in the european union this paper focuses on the harmonization of feed in laws in the european union as a support mechanism for the promotion of renewable electricity in particular it proposes a methodology for harmonization based on a feed in law with a modular and transparent premium for renewable electricity producers this premium considers technology costs some grid services political incentives and national priorities the proposed approach includes flexibility mechanisms to update and revise premiums to avoid windfall profits for producers and to share technology innovation benefits with electricity consumers while maintaining incentives for innovation our approach is based on the review of the main features of the german and spanish feed in laws and takes into account other necessary considerations for harmonization such as grid access funding definitions and standards ownership of rights derived from renewables and exceptions for small non commercial producers and energy intensive industries

non walrasian equilibria and the law of one price abstract we present a market game which features multiple posts for each commodity we use this framework to illustrate the idea that in non walrasian markets where individual activities influence market clearing prices there are equilibria where commodities are exchanged simultaneously in two posts at different prices thus defying the law of one price such equilibria are compatible with an apparent arbitrage possibility which dissipates whenever individuals try to take advantage of it

labor market discrimination against hispanic and black men h ispanic american men have lower average wage rates than white non hispanics in 1975 the average white non hispanic male wage earner in the united states earned 5 97 an hour mexican men earned 4 31 72 as much as white non hispanics puerto rican men earned 4 52 76 as much and cuban men earned 5 33 89 as much as white non hispanics by way of comparison black men s average wages in 1975 were 4 65 78 of the white male wage several possible reasons for the hispanics lower wages come to mind among them are age and education geographic location immigration language difficulties and discrimination for example as shown in table 1 mexicans and puerto ricans are younger on average than the white non hispanic population and earnings tend to rise with age hispanics have lower average levels of education than white non hispanics and wages are positively associated with education many mexican americans live in the southwest where prices are relatively low moreover hispanics are more likely to be recent immigrants and to lack fluency in english than white non hispanics and so to be at a disadvantage in the labor market in addition there is a widespread belief that hispanics suffer from employment discrimination and cannot obtain the wages that their human capital would command if they were non hispanic whites how much of the wage differentials described above are due to each of these factors and to other inter group differences in wage related characteristics in particular how much impact does labor market discrimination have on the average hispanic man s wage and how does this compare with discrimination against blacks this paper provides answers to these questions a few other efforts have been made to analyze the relative earnings of hispanic and white nonhispanic men using 1960 and 1970 census data fogel 1966 poston and alvirez 1973 poston alvirez and tienda 1976 long 1977 and gwartney and long 1978 we use more recent data from the 1976 survey of income and education this data set enables us to measure wage rates more accurately and to specify the wage function more completely than does the census unlike previous analysts in estimating the wage function we take account of possible selectivity bias due to the distinction between average wage offers and average observed wages thus we hope to obtain a more accurate and up to date measure of labor market discrimination against hispanic men section ii explains the method used to separate the minority white non hispanic wage differential into the portions due to differences in average characteristics and the portion due to differences in unobserved factors and discrimination taking into account the possibility of selectivity bias in the observed wage sample section iii describes the data used in the study and the specification of the wage equation the breakdown of the observed wage differentials into components due to differences in participation in the wage and salary sector local price levels average characteristics and discrimination are presented in section iv section v summarizes our findings and discusses their implications for efforts to improve the economic situation of hispanics in the united states

immigrant earnings relative to what the importance of earnings function specification and comparison points immigrant relative earnings estimates are sensitive to the choice of comparison point and the specification of earnings non sample mean comparisons borjas 1985 understate relative earnings simple earnings specifications linear education quadratic experience overstate relative earnings for both poorly and well educated immigrants specifications which ignore omitted variables understate the relative earnings of poorly educated immigrants and overstate those of well educated ones although measures of assimilation and changes in immigrant quality are insensitive to earnings specification they indicate strong earnings growth for post 1964 immigrants an overall decrease in immigrant quality and an increase in mexican immigrant quality

racial diversity and aggregate productivity in u s industries 1980 2000 author affiliation chad sparber department of economics colgate university 13 oak drive hamilton ny 13346 usa csparber mail colgate edu acknowledgment i would like to acknowledge the guidance and advice from the faculty and graduate students of the university of california davis i especially thank giovanni peri hilary w hoynes alan m taylor florence bouvet and ahmed s rahman three anonymous referees rukmani gounder margriet caswell and the attendees of the western economics association international conference in san francisco provided helpful comments and suggestions as did takao kato robert w turner and faculty members of colgate university and san diego state university a fellowship from the university of california office of the president provided support for this research 1 introductionthe united states grew increasingly diverse between 1980 and 2000 as whites declined from 83 to 73 of the labor force many states are reconsidering their affirmative action policies while the federal government reevaluates immigration and citizenship statutes unfortunately we do not yet fully understand the aggregate effects of diversity international empirical analyses often argue that racial or ethnic heterogeneity hinders macroeconomic growth and development by fostering conflict corruption political instability and competitive rent seeking many top u s business executives reject these views however and claim that individuals from varied backgrounds bring unique approaches to problem solving and complement each other in production several academic analyses echo these sentiments this paper adds to the debate on the costs and benefits of diversity by building upon the traditional economic growth and development framework to measure racial diversity s net effect on productivity within sectors of the united states my methodology advances the existing literature by addressing two limitations of prior studies first although cross country evidence for the costs of diversity is clear the united states may be especially effective in managing diversity this paper determines whether the u s experience differs from international accounts second typical international growth analyses measure aggregate outcomes for countries but fail to address differences in marginal effects that could exist across sectors of the economy i depart from this strategy by analyzing industrial performance across u s states to begin i measure racial diversity by using decennial census data from the integrated public use microdata series ipums 1 to construct fractionalization indices for state industry cells between 1980 and 2000 i then employ two stage weighted least squares regressions with fixed effects to estimate diversity s industry specific influence on average wages paid to workers a proxy for labor productivity in the absence of observed output per worker measures unqualified statements regarding the costs and merits of diversity are unwarranted as racial heterogeneity increases productivity within most but not all u s industries these results are robust to methodologies controlling for individual level heterogeneity state specific trends industry specific trends and supply factors prior academic research anecdotes from political events and the sector specific coefficients in this paper provide intuition about the industrial characteristics that determine whether diversity leads to economic gains or losses i use the u s department of labor s o net consortium data2 to show that industries heavily reliant upon creative decision making problem solving and customer service benefit from diversity in contrast sectors characterized by high levels of group work or teamwork experience losses which suggests that heterogeneity encumbers common action the results therefore reconcile competing literatures by recognizing both the costs and the benefits of diversity

the labor market impact of high skill immigration the rapid growth in the number of foreign students enrolled in american universities has transformed the higher education system particularly at the graduate level many of these newly minted doctorates remain in the united states after receiving their doctoral degrees so that the foreign student influx can have a significant impact in the labor market for high skill workers using data drawn from the survey of earned doctorates and the survey of doctoral recipients the study shows that a foreign student influx into a particular doctoral field at a particular time had a significant and adverse effect on the earnings of doctorates in that field who graduated at roughly the same time a 10 percent immigration induced increase in the supply of doctorates lowers the wage of competing workers by about 3 percent this abstract was borrowed from another version of this item

transportation costs and international trade in the second era of globalization while the precise causes of postwar trade growth are not well understood declines in transport costs top the lists of usual suspects however there is remarkably little systematic evidence documenting the decline this paper brings to bear an eclectic mix of data in order to provide a detailed accounting of the time series pattern of shipping costs the ad valorem impact of ocean shipping costs is not much lower today than in the 1950s with technological advances largely trumped by adverse cost shocks in contrast air shipping costs have dropped an order of magnitude and airborne trade has grown rapidly as a result as a result international trade has also experienced a significant rise in speed

the economics of immigration this literature review concerns the impact of immigration on the economy of the host country focusing on the experience of the united states the emphasis is on the period from the 1970s to the 1990s the author shows that research earlier in this period generally concluded that the economic effects of immigration were positive but that more recent research on later migrations have generally concluded that immigration may be having an adverse effect on the earnings of native unskilled workers and be placing an increased burden on welfare programs the importance of such economic analysis for the formulation of appropriate migration policies is stressed

supply amount and marginal price of renewable electricity under the renewables portfolio standard in japan abstract the renewables portfolio standard rps in japan requires that approximately 1 35 of each retail supplier s electricity sales in fy2010 come from renewable energy sources res for example photovoltaics wind biomass geothermal and small hydropower to help retail suppliers and renewable generators develop effective strategies this study provides a quantitative analysis of the impact of this measure we assume the supply conditions for electricity generation from renewable energy sources res e based on regional resource endowments and we derive the cost effective compositions of renewable portfolios res e certificate prices and additional costs to retail suppliers the future prospects of res e are assessed based on technology region and year up to fy2010 the analysis reveals that wind power and biomass power generated from municipal waste will provide the majority of the total supply of res e under the rps it also indicates that the marginal price of res e certificates will be approximately 5 8 jpy kwh 5 2 usc kwh in fy2010 in the case wherein the marginal price of electricity is assumed to be 4 jpy kwh 3 6 usc kwh in order to elaborate on this further sensitivity analyses for some parameters of res and the price of electricity are provided the dynamic supply curves of res e certificates are also indicated

immigrant worker assimilation is it a labor market phenomenon the work in this paper contributes to the debate on the economic assimilation of immigrant workers in the u s labor market a model of simultaneous occupational choice and earnings is estimated for foreign born hispanic men foreign born east asian men and for native white men to test the general hypotheses of assimilation an important distinction is made between those who migrated as adults and those who migrated as children the results suggest that the appearance of assimilation may be the outcome of pre labor market experiences of individuals who migrate as children along with changes in u s immigration law that have relaxed skill criteria for entering immigrants

valuation for renewable energy a comparative review abstract environmental cost benefit analysis is applied for the evaluation of renewable energy projects since some benefits and costs do not have monetary values economic valuation techniques are applied to estimate them this paper reviews the literature on the valuation evaluation of renewable energy resources and summarizes the methods used in them it discerns four main streams of valuation in renewable energy the first is economic welfare oriented and comprises stated and revealed preference methods the second is the financial option analysis with a financial background the third is emergy analysis which is mostly an ecological engineering based method with capable economic links and the fourth is again economic but not welfare based the paper discusses the main directions discerned in these studies and recognizes first that proper valuation takes place only in the first method while the other methods describe only evaluation procedures and second that there is a research gap that has yet to be filled in as compared to other areas of environmental resource and energy economics

time of day pricing and the levelized cost of intermittent power generation abstract an important characteristic of most renewable energy sources is intermittency in their ability to generate electricity yet intermittency is usually ignored in life cycle cost calculations intended to assess the competitiveness of electric power from renewable as opposed to dispatchable energy sources such as fossil fuels this paper demonstrates that for intermittent renewable power sources a traditional life cycle cost calculation should be appended by a correction factor which we term the co variation coefficient it captures any synergies or complementarities between the time varying patterns of electricity generation and pricing we estimate the co variation coefficient for specific settings in the western united states our estimates imply that the benchmark of cost competitiveness for solar photovoltaic pv power is 10 to 15 lower than previous average life cycle cost analyses have suggested in contrast the generation pattern of wind power exhibits complementarities with electricity pricing schedules yielding a cost assessment that is higher than that suggested by traditional calculations for the specific settings we study the corresponding magnitude of the markup is 10 to 15

china s electricity market restructuring and technology mandates plant level evidence for changing operational efficiency abstract china s electricity sector has experienced substantial efficiency improvement during the last one and a half decades the recent literature has mostly attributed the efficiency improvement to the 2002 unbundling reform with little attention paid to the large scale retrofitting process introduced by technology mandates using a unique panel dataset for hundreds of power plants from 1997 to 2010 we are able to examine the contributions from technology mandates and market restructuring we confirm the significant contributions from the unbundling reform but more importantly technology mandates have contributed at least half of the observed efficiency improvement during this period the results have significant implications for efficiency and demand forecast in the future

networks in the modern economy mexican migrants in the u s labor market this paper attempts to identify job networks among mexican migrants in the u s labor market the empirical analysis uses data on migration patterns and labor market outcomes based on a sample of individuals belonging to multiple origin communities in mexico over a long period of time each community s network is measured by the proportion of the sampled individuals who are located at the destination the united states in any year we verify that the same individual is more likely to be employed and to hold a higher paying nonagricultural job when his network is exogenously larger by including individual fixed effects in the employment and occupation regressions and by using rainfall in the origin community as an instrument for the size of the network at the destination

canadian immigration policy the effectiveness of the point system and other instruments this paper examines the effects of changes in canadian immigration policy on the occupational composition of immigration we focus on 1967 changes that created a regulatory system including the point system that still forms the framework of canadian immigration policy we find that the point system provides some control over occupational composition but that its effectiveness in fine tuning is limited by the large number of other characteristics it seeks to control we also find that entry class and source country composition of inflow have impacts that have swamped the effects of the point system in the last two decades summary in fre

the division of labor coordination costs and knowledge this paper considers specialization and the division of labor a more extensive division of labor raises productivity because returns to the time spent on tasks are usually greater to workers who concentrate on a narrower range of skills the traditional discussion of the division of labor emphasizes the limitations to specialization imposed by the extent of the market we claim that the degree of specialization is more often determined by other considerations especially emphasized are various costs of coordinating specialized workers who perform complementary tasks and the amount of general knowledge available