a century of u s farm productivity growth a surge then a slowdown u s farm productivity growth has direct consequences for sustainably feeding the world s still rapidly growing population as well as u s competitiveness in international markets using a newly expanded compilation of multifactor productivity mfp estimates and associated partial factor productivity pfp measures we examine changes in the pattern of u s agricultural productivity growth over the past century and more considering the evidence as a whole we detect sizable and significant slowdowns in the rate of productivity growth in recent decades u s multifactor productivity grew at an annual average rate of just 1 16 per year during 1990 2007 compared with 1 42 per year for the period 1910 2007 u s yields of major crops grew at an annual average rate of 1 17 per year for 1990 2009 compared with 1 81 per year for 1936 1990 more subtly but with potentially profound implications the relatively high rates of mfp growth during the third quarter of the century are an historical aberration relative to the long run trend

no free ride to zero emissions simulating a region s need to implement its own zero emissions vehicle zev mandate to achieve 2050 ghg targets abstract the adoption of zero emission vehicles zevs is limited by a variety of barriers some are region specific e g availability of charging infrastructure while others are global in nature e g battery prices where improvements spill over between regions this study explores regional spillover effects and ghg impacts of strong zev focused policy specifically the zev mandate in place in ten u s states zev states which requires automakers to sell a minimum amount of zevs each year we use a dynamic technology adoption model to simulate passenger vehicle sectors in north america focusing on the case of one small region british columbia covering 0 7 of the market as potentially free riding off of zev states policy covering 23 of the market results indicate that free ridership is not effective even with the zev mandate driving very high sales in zev states british columbia cannot achieve significant zev adoption without also implementing its own zev mandate further for british columbia to meet its 2050 ghg targets it may need a zev mandate in addition to complementary climate policies pushing zevs to account for 40 93 of new vehicle sales in 2050 in short regions seeking low carbon transportation likely need to implement their own stringent policies

campaign contributions and congressional voting a simultaneous probit tobit model m any citizens and scholars have been troubled by the influence that special interest groups appear to exert over policymaking as a result of their roles in the financing of political campaigns these concerns inspired the enactment of a number of election law reforms in the 1970s and have led to increasing popular support for public financing of electoral campaigns despite the public attention these issues have attracted few social scientists have attempted to analyze the financial relationships between interest groups and policymakers empirically 1 one such study was reported by durden and silberman 1976 who included contributions from the afl cio political action committee as an independent variable in an equation explaining congressional voting on minimum wage legislation their results indicated that campaign contributions significantly affected voting on that issue the work i have done differs substantially from that of durden and silberman in two ways first i have chosen to examine issues which were of considerably narrower concern than the minimum wage issue in the interest of simplicity i examine issues of concern to just one or a few groups i have also used a different econometric technique if campaign contributions are actually endogenous as seems plausible the single equation estimation technique employed by durden and silberman is subject to a possible simultaneous equations bias for each issue studied i have therefore jointly estimated a two equation system explaining both votes on the bill and contributions from an associated interest group the simultaneous probit tobit model which i use takes into account the dichotomous nature of the variable indicating a congressman s vote the non negativity constraint imposed on the contribution variable and the possibility of correlation between the error terms for the equations explaining these two variables 2 full information maximum likelihood fiml estimates for the model are consistent and asymptotically efficient

a spatial model of legislative voting with perceptual error this paper presents a unidimensional spatial model of voting in which members of congress vote based on an imprecise perception of roll call alternatives the model is applied to the senate roll call votes of 1977 to estimate the ideal points of the senators and to examine the role of a liberal conservative dimension in describing votes on economic issues relative to social issues in light of the spatial model the paper argues that standard models of roll call voting are not based on a theory of choice and hence that it is difficult to interpret their results alternatives to standard models based on the spatial model are developed and are used to analyze the role of ideology in deciding a specific economic issue coal strip mining

a test of the structure of pac contracts an analysis of house gun control votes in the 1980s enactment of the bill was a major victory for the national rifle association which had worked for years to win relaxation of the landmark gun control act of 1968 congressional quarterly almanac 1986 p 82 i introduction every election the same political action committees pacs contribute millions of dollars to candidates for office well informed participants in the political process surely must get value for their money yet empirical research fails to provide systematic evidence that campaign contributions influence congressional roll call votes 1 a mischaracterization of the exchange between pacs and politicians may produce these contradictory results empirical studies of roll call voting typically use pac contributions from only one election cycle earlier studies generally assume prepayment in the prior congress while more contemporary studies assume a spot exchange recent empirical work however suggests another possibility interest groups may buy current influence with money spent over multiple election cycles stratmann 1995 shows that contributions from both the current and the previous election cycles influence floor votes on agricultural price supports snyder 1990 1992 presents evidence that interest groups make long term investments in politicians previous studies by arbitrarily imposing a payment structure may have produced erroneous estimates of the influence of pac money on legislative votes we examine roll call votes on gun control in the u s house of representatives during the 1980s to determine whether pacs make spot market purchases prepay for votes in the prior election cycle or make long term investments we investigate whether pac contributions have a durable long term investment effect as snyder 1992 suggests we consider two types of evidence concerning the campaign contribution contract first we examine the pattern of expenditures by the two dominant interest groups concerned with gun control the national rifle association nra and hand gun control hgc their expenditures provide strong evidence against the spot market exchange hypothesis both groups made significant expenditures in sessions of congress in which no floor vote occurred nor were these expenditures purchasing services such as committee work in a spot market exchange further 1986 nra expenditures are significantly higher for first term representatives which is consistent with long term investments but contradicts a spot exchange since freshmen have the least influence to sell second we include expenditures from both the current and the five previous election cycles as separate independent variables in a model of roll call voting to date no empirical paper tests whether pac money from more than two cycles influences roll call voting and only stratmann 1995 and grenzke 1989 use a model that specifies money from more than one cycle in an equation explaining roll call votes our probit estimates indicate that nra expenditures in the three most recent election cycles and hgc expenditures in the two most recent cycles buy votes the independent effect of expenditures from different cycles suggests that contributions are neither an unqualified one session prepayment nor a spot exchange the influence of nra expenditures two sessions prior to the roll call votes is evidence of a long term investment the literature on the determinants of roll call voting assumes that pac contributions alter representatives votes interest groups might instead simply provide campaign assistance to their supporters to affect the composition of congress stratmann 1991 bronars and lott 1997 if a difficult to quantify variable and thus omitted from regressions signals a representative s true position and interest groups make campaign contributions on the basis of this variable pac contributions might appear to influence votes the pattern of contributions and votes on gun control however indicates attempts by the nra and hgc to influence votes not merely the composition of congress

a general equilibrium model of congressional voting in this paper we specify a model in which congressmen constituents and campaign contributors simultaneously decide on behavior constituents and contributors desire to influence the voting behavior of congressmen congressmen on the other hand want to be elected and vote accordingly we empirically test this model using roll call voting on eight bills dealing with economic regulation and find support for the model our results indicate that part of the voting behavior of congressmen may be explained by noneconomic factors we also find that unions and businesses as campaign contributors are sometimes influential unions are more often influential than is business ideological factors are also important in explaining voting

long term behaviour of co2 emissions from cement production in spain scenario analysis using an energy optimisation model abstract during the past decade the spanish cement production industry has experienced constant technological updates nevertheless meeting current and future environmental policy goals requires extra efforts the spanish case is significant because cement production went down dramatically due to the last economic crisis this brought an important but temporary reduction of co2 emissions therefore there is an interesting opportunity for cement producers and policymakers to adjust the long term targets this work discusses the evolution of the cement industry in spain from a realistic point of view using recent cement demand projections and the times spain energy optimisation model several environmental friendly options were implemented in times spain following a literature review these measures aimed at contributing to the decrease of emissions to meet the established policy goals include energy efficiency improvements substitution scenarios both for fuel and materials and co2 capture post combustion and oxyfuel from a policy approach the deployment of the eu ets directive entails that co2 emissions from cement production will decrease by 8 mt per year from 2030 with respect to the case without directive in a more technology specific analysis a remarkable decrease of 2 2 4 mt co2 was obtained in the material substitution scenario beyond 2030 additionally taking into account current projections for cement demand co2 capture technology does not emerge as a feasible option only if cement demand grew back to the pre crisis level by 2050 and the co2 emission allowances remained fixed would the co2 capture via post combustion start to be a reasonable alternative

evaluating relative benefits of different types of r d for clean energy technologies clean energy technologies that cost more than fossil fuel technologies require support through research and development r d learning by doing relates historical cost decreases to accumulation of experience a learning investment is the amount of subsidy that is required to reach cost parity between a new technology and a conventional technology we use learning investments to compare the relative impacts of two stylized types of r d we define curve following r d to be r d that lowers costs by producing knowledge that would have otherwise been gained through learning by doing we define curve shifting r d to be r d that lowers costs by producing innovations that would not have occurred through learning by doing we show that if an equal investment in curve following or curve shifting r d would produce the same reduction in cost the curve shifting r d would be more effective at reducing the learning investment needed to make the technology competitive the relative benefit of curve shifting over curve following r d is greater with a high starting cost and low learning rate our analysis suggests that other things equal investments in curve shifting r d have large benefits relative to curve following r d in setting research policy governments should consider the greater benefits of cost reductions brought about by transformational rather than incremental change

achieving california s 80 greenhouse gas reduction target in 2050 technology policy and scenario analysis using ca times energy economic systems model the ca times optimization model of the california energy system v1 5 is used to understand how california can meet the 2050 targets for greenhouse gas ghg emissions 80 below 1990 levels this model represents energy supply and demand sectors in california and simulates the technology and resource requirements needed to meet projected energy service demands the model includes assumptions on policy constraints as well as technology and resource costs and availability multiple scenarios are developed to analyze the changes and investments in low carbon electricity generation alternative fuels and advanced vehicles in transportation resource utilization and efficiency improvements across many sectors results show that major energy transformations are needed but that achieving the 80 reduction goal for california is possible at reasonable average carbon reduction cost 9 to 124 tonne co2e at 4 discount rate relative to a baseline scenario availability of low carbon resources such as nuclear power carbon capture and sequestration ccs biofuels wind and solar generation and demand reduction all serve to lower the mitigation costs but ccs is a key technology for achieving the lowest mitigation costs

conflict of interest and congressional voting a note results of this study are consistent with those of previous voting studies which have shown that party ideology and constituency characteristics are often significant explanatory variables in equations to explain voting no evidence was found to support the hypothesis that congressmen s voting decisions depend upon their private financial interests this suggests the conclusion that much of the concern about apparent conflicts of interest is unfounded but it must be recognized that this study has examined voting on just a few issues and has used data on financial holdings which were lacking in precision as more data becomes available in the next several years we should be able to resolve this question with greater confidence

incomplete information and ideological explanations of platform divergence one of the paradoxes of formal spatial voting models is the robustness of the theoretical result that candidates will converge toward centrists positions and the empirical observation of persistent policy divergence of candidates a solution is that candidates are ideological have policy preferences when candidates have policy preferences and incomplete information about voter preferences then platform divergence is theoretically predicted experimental tests of the ideological model are presented it is shown that platform divergence is significant when candidates are ideological and have incomplete information about voter preferences however candidate positions are more convergent on average than the theory predicts suggesting that subjects value winning independently of the expected payment

post war productivity patterns in u s agriculture influences of aggregation procedures in a state level analysis annual data for forty eight states are used to account for changes in the composition of input and output aggregates over space and time and thereby to obtain new evidence on changes in inputs outputs and productivity in u s agriculture the measures change significantly when we use state specific rather than national prices and when we allow for changes in the composition of the aggregates especially of labor and capital inputs we compare our estimates and those reported by ball et al american journal of agricultural economics 81 1999 164 79 the national estimates are similar but substantial differences are found in state level productivity growth

a review of low carbon fuel policies principles program status and future directions a low carbon fuel standard lcfs is a market based policy that specifies declining standards for the average lifecycle fuel carbon intensity afci of transportation fuels sold in a region this paper i compares transportation fuel carbon policies in terms of their economic efficiency fuel price impacts greenhouse gas emission reductions and incentives for innovation ii discusses key regulatory design features of lcfs policies and iii provides an update on the implementation status of lcfs policies in california the european union british columbia and oregon the economics literature finds that an intensity standard implicitly taxes emissions and subsidizes output the output subsidy results in an intensity standard being inferior to a carbon tax in a first best world although the inefficiency can be corrected with a properly designed consumption tax or mitigated by a properly designed carbon tax or cap and trade program in california from 2011 to 2015 the share of alternative fuels in the regulated transportation fuels pool increased by 30 and the reported afci of all alternative fuels declined 21 lcfs credit prices have varied considerably rising to above 100 credit in the first half of 2016 lcfs programs in other jurisdictions share many features with california s but have distinct provisions as well c 2016 elsevier ltd all rights reserved

environmental protection a theory of direct and indirect competition for political influence how is it that environmental groups can have a strong impact on environmental policy but without much lobbying this paper develops a model of direct lobbying the government and indirect persuading the public competition for political influence and finds that they are complementary however an increase in the effectiveness of public persuasion or a rise of public environmental awareness induces substitution between the two the findings establish that the empirical phenomenon of lack of political contribution from environmental groups may not be related to financial constraints but to their greater effectiveness in public persuasion and growing public environmental awareness the size of its economic stake and hence the associated lobbying effort and the efficiency of its organization in exerting political influence how then can we explain why some environmental groups have been very successful against polluting industries when the latter s economic stakes seem very high and they lobby more and their interests are more efficiently organized some might suggest that the reason for the success of the environmental movement is that environmental groups have large memberships and can provide block votes 2 however according to olson 1965 a large membership of an interest group is not necessarily an advantage and it is still uncertain whether environmental groups are able to mobilize their members to cast votes based on such affiliations this paper suggests an alternative explanation by developing a theory of direct and indirect competition between special interests for political influence rather than marshalling block votes a primary feature of our framework is that two opposing interest groups an environmentalist group and an industrialist group compete directly and indirectly for political influence in a three stage game the indirect competition takes place in the first stage in which interest groups exert effort in persuading the public to indirectly influence government policy the direct competition takes place in the second stage in which interest groups exert effort in

reflections on agricultural r d productivity and the data constraint unfinished business unsettled issues sixty years ago t w schultz introduced the idea of the productivity residual to agricultural economics 1956 schultz s main message was that growth in conventional inputs accounted for little of the observed growth in agricultural output and that there was work to be done by agricultural economists to understand and ultimately eliminate this unexplained residual called productivity thus was launched the economics of agricultural productivity as a sub field within agricultural economics along with the economics of agricultural r d and innovation and related government policy much progress has been made in the decades since still critical issues remain unresolved this matters because agricultural innovation and productivity matter and so do the related policies that rest to some extent on our established understanding of the economic relationships in this paper i review some unsettled issues related to economic models and measures applied to agricultural r d and productivity and some unfinished business in terms of economic and policy questions that are not yet well answered before doing that i present some evidence on agricultural productivity and why it matters next with a nod to factology i present available productivity measures from the u s department of agriculture usda and international science and technology practice and policy instepp center and compare them in the context of translog cost function models in subsequent sections i use these and other data to develop new evidence related to two contentious questions a do farmers benefit from public agricultural r d b has u s agricultural productivity growth slowed in recent decades the answers are revealed within

the theory of economic regulation and public choice and the determinants of public sector bargaining legislation in this study we used the theory of economic regulation and public choice to derive a model to explain the pattern of public sector bargaining laws among the states we find this type of legislation is influenced by the following demand factors 1 the extent of public sector union membership which represents the interest group hypothesis has a positive influence on pro union legislation 2 the extent of employer opposition to unions as measured by unfair labor practice charges against employers in representation elections has a negative effect on bargaining laws 3 two taste variables the salaries of public employees and the percent of nonwhite employment in the state have a positive influence on these laws a result which will be surprising to many people is that the extent of private sector union membership has no significant influence on the passage of public sector bargaining legislation

the next generation of urban maccs reassessing the cost effectiveness of urban mitigation options by integrating a systemic approach and social costs abstract many cities are implementing policies and climate action plans yet local climate policies suffer from a lack of scientific understanding and evaluation methods able to support the definition of efficient mitigation strategies the purpose of this paper is to build on classical approaches in the energy policy field that exist at the national and international level to propose an urban maccs methodology able to fulfill this lack and inform local debates the methodology is an extension of static expert based maccs it combines a land use transport integrated model and an abatement cost methodology that integrates co benefits and takes into account the spatial and systemic dimensions of cities the methodology is implemented for the transportation sector of a mid sized european city grenoble france our results present the cost effectiveness and political feasibility of several proposed measures we find that the inclusion of co benefits can profoundly change the cost benefit assessment of transport mitigation options moreover we underline the key parameters determining the cost effectiveness ranking of mitigation options these urban maccs aim to serve as a bridge between urban planning and mitigation policies and can thus contribute to strengthen and align sustainable and climate change agendas at the local level

capital services in u s agriculture concepts comparisons and the treatment of interest rates this paper begins with a review of the methods and assumptions used to measure capital service flows two data series on capital inputs in u s agriculture are briefly described and compared we show that measures of capital services are sensitive to the treatment of interest rates notably the use of fixed versus variable market rates significantly affects measures of the quantity and productivity of agricultural capital in the united states we conclude that when calculating capital usage in u s agriculture the use of a fixed interest rate generates more plausible estimates than the use of an annual market rate

high resolution modeling of the western north american power system demonstrates low cost and low carbon futures decarbonizing electricity production is central to reducing greenhouse gas emissions exploiting intermittent renewable energy resources demands power system planning models with high temporal and spatial resolution we use a mixed integer linear programming model switch to analyze leastcost generation storage and transmission capacity expansion for western north america under various policy and cost scenarios current renewable portfolio standards are shown to be insufficient to meet emission reduction targets by 2030 without new policy with stronger carbon policy consistent with a 450 ppm climate stabilization scenario power sector emissions can be reduced to 54 of 1990 levels by 2030 using different portfolios of existing generation technologies under a range of resource cost scenarios most coal power plants would be replaced by solar wind gas and or nuclear generation with intermittent renewable sources providing at least 17 and as much as 29 of total power by 2030 the carbon price to induce these deep carbon emission reductions is high but assuming carbon price revenues are reinvested in the power sector the cost of power is found to increase by at most 20 relative to business as usual projections

the ideological component of senate voting different principles or different principals evidence exists on both sides of the question of whether or not legislator specific ideologically driven shirking of constituent interest occurs in this paper we use a well known model of such shirking by senators as our point of departure and add measures of inter state constituent interests the role of campaign contributions and hence the importance of whether or not senators are up for reelection we find some evidence that the model provides a stronger explanation for senators up for reelection than for those who are not and that campaign contributions help determine voting decisions by these legislators finally accounting for inter state constituent interests shirking is not a significant variable in the voting decisions of senators facing reelection thus it appears that the reelection interests of some senators have been mistaken for ideologically driven shirking

legislator voting and shirking a critical review of the literature we set out to critically review the progress in answering two related questions what determines how legislators vote and how can shirking by legislators be measured in the first category the hypothesis that legislators shirk in order to indulge their personal ideological preferences has led researchers astray the theoretical underpinning is shaky on two counts first legislators who indulge their preferences at the expense of their constituents preferences put themselves at a competitive electoral disadvantage second the original two stage procedure used to measure ideological shirking is severely flawed among many other problems the residual measure of shirking implicitly assumes that the median voter is the relevant constituent principal for the legislator agent

passing the food and agricultural r d buck the united states and china abstract the global geographical balance of food and agricultural r d spending is shifting characterized by a declining u s share and a rising middle income country share propelled heavily by the rapid rise of spending in china based on our newly compiled data we estimate that china now outspends the united states on both public and private food and agricultural research on a purchasing power parity basis the public private orientation of the research has also changed markedly with the private sector now accounting for around two thirds of the food and agricultural r d spending total in both china and the united states our estimates indicate that china s private sector tilts heavily towards post farm r d activities whereas the u s private sector is split more evenly between on farm and post farm spending while the intensity of chinese investment in food and agricultural r d relative to agricultural gdp is beginning to grow it still lags well behind the food and agricultural r d investment intensities of the united states and other higher income asian countries e g japan and south korea the development regularities we reveal in the longer run trends are indicative of future r d investment patterns with potentially profound long run implications for the size shape and accessibility of the global stocks of scientific knowledge that underpin food and agricultural sectors worldwide

theoretical production restrictions and agricultural technology in the united states agricultural production studies are usually conducted using classical econometrics that make it difficult if not impossible to impose conditions derived from economic theory on flexible functional forms therefore such conditions need not hold in estimation we apply bayesian econometrics to estimate a flexible production function using u s agricultural data under alternative restrictions dictated by theory including a fully theoretically consistent model that satisfies all restrictions at each point of the data the probability density functions of parameters output elasticities scale elasticity and productivity gains vary substantially across models output elasticities from the fully theoretically consistent model suggest that agricultural production in the united states has typically been more responsive to land than to other factors of production however output became more responsive over time to changes in materials and less responsive to changes in land and labor by the early 2000s the elasticity of output to materials was very similar to the elasticity of output to land the elasticity of output to capital remained relatively stable over the entire sample the estimates from the fully theoretically consistent model also show a slight increase in the average rate of productivity gains between the 1960s and the 1970s a relative slowdown in the 1980s and 1990s and a relative stabilization afterwards all inputs are substitutes in production all the elasticities of substitution have increased through the decades though at different rates

are contributors rational untangling strategies of political action committees empirical public choice literature and casual observation suggest that the behavior of political action committees is remarkably unsophisticated meaning that pacs give to those legislators who would support their interests anyway thus it is suggested that contributor behavior deviates from rational behavior which is a cornerstone of economic analysis in this paper a switching regression model is estimated that allows for strategies of pacs to vary for different contribution recipients i analyze the behavior of farm pacs over three election cycles in contrast to previous findings i find that contributor behavior is not inconsistent with rational behavior contributors who attempt to influence the voting behavior of members of congress give the most money to legislators whose constituency interest suggests that they are likely to be undecided on how to vote and pacs give less money to legislators who represent districts with larger farm populations because those legislators are likely to vote in con

uncertainty loss aversion and markets for energy efficiency increasing energy efficiency is critical to mitigating greenhouse gas emissions from fossil fuel combustion reducing oil dependence and achieving a sustainable global energy system the tendency of markets to neglect apparently cost effective energy efficiency options has been called the efficiency gap or energy paradox the market for energy efficiency in new energy using durable goods however appears to have a bias that leads to undervaluation of future energy savings relative to their expected value this paper argues that the bias is chiefly produced by the combination of substantial uncertainty about the net value of future fuel savings and the loss aversion of typical consumers this framework relies on the theory of context dependent preferences the uncertainty loss aversion bias against energy efficiency is quantifiable making it potentially correctible by policy measures the welfare economics of such policies remains unresolved data on the costs of increased fuel economy of new passenger cars taken from a national research council study illustrate how an apparently cost effective increase in energy efficiency would be uninteresting to loss averse consumers

does additional campaign spending really hurt incumbents the theoretical importance of past investments in political brand name the existing literature ignores the fact that the marginal return to current campaign expenditures depends on the candidate s stock of brand name this simple observation is then used to provide a possible explanation for the negative empirical relationship observed between an incumbent s campaign spending and how well he does