are health insurance markets competitive to gauge the competitiveness of the group health insurance industry i investigate whether health insurers charge higher premiums ceteris paribus to more profitable firms such direct price discrimination is feasible only in imperfectly competitive settings using a proprietary national database of health plans offered by a sample of large multisite firms from 1998 2005 i find firms with positive profit shocks subsequently face higher premium growth even for the same health plans moreover within a given firm those sites located in concentrated insurance markets experience the greatest premium increases the findings suggest health care insurers are exercising market power in an increasing number of geographic markets

from the classical economists to empiricists a review of the terms of trade controversy contrary to the classical position the works of prebisch and singer in the middle of the last century launched the controversial hypothesis of a long term decline in the terms of trade of primary products vis a vis manufactured goods and a corresponding decline in the terms of trade of developing countries vis a vis advanced ones the present study traces the origin and evolution of the hypothesis and reviews the related statistical debate it also reviews the theoretical support for the prebisch singer hypothesis it is an exercise in the history of economic thought to trace how the controversies surrounding the terms of trade have evolved over time specifically noting that with the development of the field of econometrics the central thesis of the argument got lost somewhere in the realm of hi tech statistical debates

the commodity terms of trade unit roots and nonlinear alternatives a smooth transition approach market price dynamics for north american oriented strand board markets are examined specifically the role of transactions costs are examined vis a vis the law of one price weekly data for the january 3rd 1995 through april 14th 2006 period are used in the analysis nonlinearities induced by unobservable transactions costs are modeled by estimating smooth transition autoregressions stars results indicate that nonlinearity is an important feature of these markets and that the parity relationships implied by economic theory are generally supported by the star models implications for the efficiency of spatial market linkages are examined by estimating generalized impulse response functions

health insurance without single crossing why healthy people have high coverage standard insurance models predict that people with high risks have high insurance coverage it is empirically documented that people with high income have lower health risks and are better insured we show that income differences between risk types lead to a violation of single crossing in an insurance model where people choose treatment intensity we analyse different market structures and show the following if insurers have market power the violation of single crossing caused by income differences and endogenous treatment choice can explain the empirically observed outcome our results do not rely on differences in risk aversion between types

pricing and welfare in health plan choice premiums in health insurance markets frequently do not reflect individual differences in costs either because consumers have private information or because prices are not risk rated this creates inefficiencies when consumers self select into plans we develop a simple econometric model to study this problem and estimate it using data on small employers we find a welfare loss of 2 11 percent of coverage costs compared to what is feasible with risk rating only about one quarter of this is due to inefficiently chosen uniform contribution levels we also investigate the reclassification risk created by risk rating individual incremental premiums finding only a modest welfare cost

did community rating induce an adverse selection death spiral evidence from new york pennsylvania and connecticut using data from the 1987 to 1996 march current population surveys we find no evidence for the dire predictions of some that the imposition of pure community rating leads to a market wide reduction in insurance coverage by setting off an adverse selection death spiral specifically the percentage of individuals in small groups covered by health insurance did not fall in new york which enacted community rating legislation in 1993 relative to either pennsylvania which enacted no insurance reform or connecticut which enacted moderate insurance reforms without imposing community rating consistent with the predictions of the simple rothschild and stiglitz 1976 framework however we find that the new yorkreforms appear to have had a significant impact on the structure of the new yorkinsurance mark et specifically new yorkexperienced a dramatic shift away from indemnity insurance toward hmos while this shift tookplace during a period of nationwide increases in the percentage with managed care the increase in hmo penetration in new york s small group and individual markets was significantly greater than in pennsylvania or connecticut

on why agriculture declines with economic growth abstract when economic growth is characterised by a slow rise in the demand for food and rapid growth in farm relative to non farm productivity it is understandable that agriculture in a closed economy declines in relative terms as that economy develops but why should agriculture decline in virtually all open growing economies as well including those able to retain a comparative advantage in agricultural products a key part of the answer is that the demand for non tradable goods tends to be income elastic so resources are diverted to their production even in open economies

equilibria in health exchanges adverse selection versus reclassification risk this paper studies equilibrium and welfare in a class of regulated health insurance markets known as exchanges we use detailed health plan choice and utilization data to model individual level i projected health risk and ii risk preferences we combine the estimated distributions of risk and risk preferences with a model of competitive insurance markets to predict allocations and prices

competition leverage how the demand side affects optimal risk adjustment we study optimal risk adjustment in imperfectly competitive health insurance markets when high risk consumers are less likely to switch insurer than low risk consumers insurers then have an incentive to select even if risk adjustment perfectly corrects for cost differences to achieve first best risk adjustment should overcompensate insurers for serving high risk agents second we identify a trade off between efficiency and consumer welfare reducing the difference in risk adjustment subsidies increases consumer welfare by leveraging competition from the elastic low risk market to the less elastic high risk market third mandatory pooling can increase consumer surplus further at the cost of efficiency

imperfect competition in selection markets policies to correct market power and selection can be misguided when these forces coexist we build a model of symmetric imperfect competition in selection markets that parameterizes the degree of market power and selection we use graphical price theoretic reasoning to characterize the interaction between these forces using a calibrated model of health insurance we show that the risk adjustment commonly used to offset adverse selection can reduce coverage and social surplus conversely in a calibrated model of subprime auto lending realistic levels of competition can generate an oversupply of credit implying that greater market power is desirable

some estimates of prebisch and singer effects on the terms of trade between primary producers and manufacturers abstract movements in the prices of primary products and manufactured goods are analyzed using a model based on the seminal contributions of raul prebisch and hans singer estimates are obtained from a system of equations using post wwii data on prices wages and manufacturing mark ups with the results providing evidence of the negative effects on the terms of trade of primary producers suggested by both prebisch and singer these effects more than offset positive effects arising from diminishing returns in primary production thereby providing an explanation for the negative net trend in the terms of trade of primary producers in the postwar period

the complementarity between risk adjustment and community rating distorting market outcomes to facilitate redistribution abstract we analyze optimal risk adjustment in competitive health insurance markets when insurers have better information on their customers risk profiles than the sponsor of health insurance in the optimal scheme the sponsor uses reinsurance to screen insurers with bad and good risks in order to lower premiums for enrollees with high expected healthcare costs we then explore the effects of adding a community rating requirement to complement this risk adjustment scheme with community rating insurers have incentives to distort contract generosities to cherry pick low cost consumers however the reduced generosity for low cost types makes screening through reinsurance easier allowing the sponsor to redistribute more when costs for reinsurance are low or the sponsor s bias towards high cost consumers is high community rating dominates risk rating

the endogenous transaction costs of delegated auditing abstract this paper analyzes the deadweight loss of delegated auditing in a three tier hierarchy in a costly state verification model this cost depends on the endogenous information structure the auditor s degree of risk aversion and the size of the punishment we identify the optimal contractual outcome of this delegation model with the solution obtained in a standard three tier hierarchical model of collusive auditor we then derive from this identification the set of parameters of the physical environment which may affect the efficiency of side contracting within the firm

manufactured exports of developing countries and their terms of trade since 1965 abstract during the last 40 years since the prebisch singer terms of trade deterioration hypothesis was first proposed the commodity composition of exports of developing countries has undergone a major change in the direction of dominance of manufactures in their nonfuel exports with strong growth in the volume of their manufactured exports but this did not allow developing countries to escape unequal exchange relations with the industrial countries their barter terms of trade in manufactures showed signs of weakness rather than improvement and clearly failed to reflect the respective productivity trends leading to deterioration in factoral terms of trade

self regulation and government oversight self regulation is a feature of a number of professions for example in the u s the government delegates aspects of financial market regulation to self regulatory organizations sros like the new york stock exchange and the national association of securities dealers we analyse one regulatory task of an sro enforcing antifraud rules so agents will not cheat customers specifically we model contracting enforcement as a two tier problem an sro chooses its enforcement policy the likelihood that an agent is investigated for fraud and a penalty schedule given an enforcement policy agents compete by offering contracts that maximize customers expected utility we assume that the sro s objective is to maximize the welfare of its members the agents we show that the sro chooses a more lax enforcement policy meaning less frequent investigations than what customers would choose a general conclusion is that control of the enforcement policy governing contracts confers substantial market power to a group of otherwise competitive agents we also investigate government oversight of the self regulatory process the threat of government enforcement leads to more enforcement by the sro just enough to pre empt any government enforcement copyright 2005 wiley blackwell

reinsuring risk to increase access to health insurance at least 41 million americans are currently without health insurance in any given month u s bureau of the census 2002 they are uninsured for a variety of reasons and most people who lack coverage are affected by more than one reason two generalizations can be made however first a majority simply cannot afford to purchase health insurance unless it is heavily subsidized most do not have access to employer sponsored coverage and so must purchase any insurance in the non group individual health insurance market a market where as i explain below insurance is typically twice as expensive as employer group coverage if it is not denied outright since about two thirds of the uninsured have incomes below 35 000 non group health insurance premiums often exceed 10 percent of their incomes the second generalization is that to an important extent high premiums in the non group market and denial of coverage reflect market failure due to asymmetric information insurers can never know as much as an individual does about his or her health family history of health problems and tendency to seek medical care because of this asymmetry it is impossible for an insurer to set premiums that accurately reflect the non random portion of health care costs for different individuals the non group market is the only health insurance option for people without employersponsored coverage tax related subsidies as proposed by members of congress and the bush administration do not address the market failure problems and so are unlikely to make insurance much more affordable to increase access to health insurance risk in the non group market needs to be shifted to a broader population base in what follows i first describe the three distinct health insurance markets in which people can obtain health insurance and the special nature of competition among insurance companies in the non group market then i make the case for government to act as reinsurer and assume the risk of extremely high cost people efficiency in the non group health insurance market would be improved if the government reinsured the market equity also would be increased if the government acted as reinsurer because more uninsured people would have access to insurance finally i describe precedents for this role for government in other markets and why tax related subsidies will not succeed in increasing health insurance coverage unless the risks of extremely high costs are shifted to the government

paying for health insurance the trade off between competition and adverse selection we use data on health plan choices by employees of harvard university to compare the benefits of insurance competition with the costs of adverse selection moving to a voucher type system induced significant adverse selection with a welfare loss of 2 to 4 percent of baseline spending but increased competition reduced harvard s premiums by 5 to 8 percent the premium reductions came from insurer profits so while harvard was better off the net effect for society was only the adverse selection loss adverse selection can be minimized by adjusting voucher amounts for individual risk we discuss how such a system would work governments are increasingly turning to market forces as a way to limit the cost of social insurance traditionally social insurance programs were operated as nonmarket goods governments mandated participation in a central program collected revenues to finance the program and ran the insurance system there was no role for competition among suppliers in providing the basic benefit as the costs of social insurance have increased however the centralized model of social insurance is coming under increasing strain in the united states for example recent proposals have called for replacing the medicare program with a health care voucher for the elderly aaron and reischauer 1995 cutler 1996 the voucher would guarantee people a basic insurance plan but the plans would be privately run competition among plans would generate plan premiums and enrollments similarly longstanding proposals for social security reform have called for replacing the current system with a system of individual accounts where people would make saving investment and annuitization decisions on their own advisory council on social security 1996 feldstein 1996 the trend is not just domestic in the united kingdom the national health service has moved to encourage more competition in recent years with the establishment of hospital trusts that bid for patients and partially fixed payments to physicians

do multinationals deteriorate developing countries export prices the impact of fdi on net barter terms of trade this paper explores the economic relationship between foreign direct investment fdi to developing countries and the export prices of the latter measured by terms of trade it is rst shown that economic theory suggests such a relationship for various reasons but is inconclusive about the direction of the eect to address this open issue empirically i analyze data on more than 50 developing countries throughout the period 1980 2008 using robust dynamic panel data methods the results show that fdi had an economically relevant and statistically signicant positive impact on developing countries net barter terms of trade a higher level of education in the developing country fosters this eect

how does risk selection respond to risk adjustment new evidence from the medicare advantage program to combat adverse selection governments increasingly base payments to health plans and providers on enrollees scores from risk adjustment formulae in 2004 medicare began to risk adjust capitation payments to private medicare advantage ma plans to reduce selection driven overpayments but because the variance of medical costs increases with the predicted mean incentivizing enrollment of individuals with higher scores can increase the scope for enrolling overpriced individuals with costs significantly below the formula s prediction indeed after risk adjustment ma plans enrolled individuals with higher scores but lower costs conditional on their score we find no evidence that overpayments were on net reduced

insurer pricing and consumer welfare evidence from medigap this article examines the welfare impact of imperfect competition in the medicare supplement insurance medigap market two firms control nearly three fourths of the medigap market and premiums exceed claims by over 25 i find that a low price elasticity and consumers brand preferences lead firms to engage in substantial marketing and price above cost therefore the strategic behavior of insurers facing relatively inelastic demand is critical in explaining poor market performance i also find that insurers do not capture all of the rents in this market rents also accrue to actors who perform marketing functions including agents and brokers

optimal risk adjustment in markets with adverse selection an application to managed care it is well known that adverse selection causes distortions in contracts in markets with asymmetric information taxing inefficient contracts and subsidizing the efficient ones can improve market outcomes bruce c greenwald and joseph e stiglitz 1986 although regulators rarely seem to implement tax and subsidy schemes with adverse selection motives in mind contracts are often complex and incomplete and it is the inefficient elements of the contract that are difficult to verify and hence tax or subsidize this is precisely the reason that in health insurance markets rather than subsidizing contracts regulators and payers contend with adverse selection by taxing and subsidizing the price paid to insuring health plans on the basis of observable characteristics of the persons joining the plan a practice known as risk adjustment risk adjusted premiums are paid to managed care plans plans that ration care by management rather than by conventional approaches like coinsurance and deductibles and offer a bundle of characteristics quality access for many services that is fundamentally outside the scope of direct regulation selection related incentives threaten the efficiency and fairness of this organization of health insurance markets by inducing plans to distort the quality of the services they offer to discourage high cost persons from joining the plan as managed care becomes the predominant source of health care for residents of the united states and many other countries payers attempt to address this incentive by setting a risk adjusted price that pays more for more expensive enrollees as it is conventionally practiced risk adjustment sets prices for people proportional to their expected cost based on observable characteristics the federal medicare program for example has used age sex welfare status and county of residence adjusters to set prices to managed care plans to convey how what we term conventional risk adjustment works suppose age is the risk adjuster for a medicare population over 65 if it is determined that the 75to 84 year old population costs 20 percent more than the overall average in medicare the assumption in conventional risk adjustment is that the premium paid to plans for someone in this group should be 20 percent above the average we fundamentally disagree that this is the right way to think about and do risk adjustment

the statistical debate on the net barter terms of trade between primary commodities and manufactures a comment and some additional evidence i950 p s hypothesis according to this hypothesis the net barter terms of trade nbtt between primary products and manufactures have over the longrun exhibited a downward trend spraos presented a detailed and thorough analysis of both the adequacy of the various statistical series available to proxy the nbtt s behaviour over the long run and the wide range of conceptual including quality problems involved in such an exercise on the basis of his analysis spraos concluded that the balance of the evidence for the seventy year period ending with the outbreak of world war ii supported the p s hypothesis of a secular deterioration in the nbtt it should however be noted that the evidence also suggested that the particular series cho sen for analysis by prebisch i950 himself did appear to exaggerate possibly to a large extent the rate of deterioration however when the analysis was extended to include the post world war ii period spraos found that while the deteriorating tendency cannot be decisively refuted it is open to doubt when the record up to the i970s is taken into account i980 p i26 as we shall see in this paper closer scrutiny reveals a statistical problem with spraos s analysis and the purpose of this paper is to show that once appropriate action is taken to overcome this problem some quite strong evidence in support of the p s hypothesis emerges the paper is organised as follows section i briefly discusses spraos s methodology and section ii discusses an econometric issue arising from this analysis section iii presents our empirical evidence while section iv summarises the main findings of the paper

minimum wage effects under endogenous compliance evidence from peru latin american labor markets feature large informal sectors in practice however the simple duality formal informal has many different shades firms tend to comply more with certain legislation than with other recent evidence has suggested that minimum wages have significant effects on the informal sector bell 1997 for mexico gindling and terrell 2004 for costa rica lemos 2004 and fajnzylver 2001 for brazil and maloney and nunez 2004 for colombia further some of this evidence suggests effects throughout a large part of the wage distribution this has been interpreted as evidence of lighthouse or numeraire effects we test this hypothesis using panel data from peru to identify effects throughout the wage distribution although there are some effects on informal sector workers overall results provide little support for numeraire or lighthouse effects labor monthly earnings are affected only at the bottom of the distribution 0 25 0 60 of the minimum wage made up mostly of informal workers and for formal workers earning between the old the new minima negative effects on the probability of retaining employed status after a minimum wage shock are either weak or non significant for wage earners below the minimum wage but significant for formal workers trapped between minima and for both formal and informal earning between 1 2 and 2 times the minimum wage independent workers earning below minimum suffer negative effects on both earnings and employment

the prebisch singer hypothesis a reappraisal independent of stationarity hypotheses time series behaviour of the relative price of primary commodities raul prebisch i950 and hans singer i950 believed that the long term trend of primary commodity prices was negative the latter in an interesting discussion of the above quandary pp 482 3 viewed rises in primary commodity prices as purely temporary sources of surplus that offered short lived opportunities to increase industrial investment these opportunities were missed by private investors who instead increased primary sector investment in such circumstances because all private activity tends to be governed by the price