walrasian equilibrium with gross substitutes in this paper we study the problem of efficient production and allocation of indivisible objects among a set of consumers we assume that the agents preferences depend on the bundle of objects and the quantity of money they consume furthermore we assume that preferences are quasilinear in money and that agents have a large endowment of money with indivisibilities it is well known that many familiar properties of the utility functions fail to ensure existence in their striking analysis of the matching problem kelso and crawford 5 introduce the gross substitutes gs condition which ensures the non emptiness of the core we propose two new conditions and show that with quasilinearity they are equivalent article id jeth 1999 2531 available online at http www idealibrary com on

agricultural competitiveness the case of the united states and major eu countries abstract growth in the agricultural gdp of four major european countries is compared with us agricultural growth for the period 1974 1993 the agricultural sector s relative prices are taken into account along with economy wide factor market adjustments for denmark france germany and the uk the effects of declining real prices and changes in input levels on growth in agricultural gdp are relatively small total factor productivity tfp growth appears to be the major contributor to european agricultural gdp growth in comparison tfp is the major source of growth in us agricultural gdp but its rate of growth is lower than the european countries in contrast the declining real prices for us agriculture had a relatively large effect on its gdp however in recent years the effects of declining real prices and declining rates of growth in tfp on european agriculture are relatively large in the longer run the relative competitiveness of us agriculture is largely dependent on its ability to sustain and increase growth in tfp

multi item vickrey dutch auctions descending price auctions are adopted for goods that must be sold quickly and in private values environments for instance in flower fish and tobacco auctions in this paper we introduce ex post efficient descending auctions for two environments multiple non identical items and buyers with unit demand valuations and multiple identical items and buyers with non increasing marginal values our auctions are designed using the notion of universal competitive equilibrium uce prices and they terminate with uce prices from which the vickrey payments can be determined for the unit demand setting our auction maintains linear and anonymous prices for the homogeneous items setting our auction maintains a single price and adopts ausubel s notion of clinching to compute the final payments dynamically the auctions support truthful bidding in an ex post nash equilibrium and terminate with an ex post efficient allocation in simulation we illustrate the speed and elicitation advantages of these auctions over their ascending price counterparts

financial literacy and mortgage equity withdrawals abstract mortgage equity withdrawals mew are correlated with covariates consistent with a permanent income framework augmented for credit constraints we assess linkages between mew and financial literacy education using the health and retirement study hrs and panel study of income dynamics psid we find that the financially literate are 3 5 percentage points less likely to withdraw housing equity via non home equity loan mortgages using the hrs while college graduates are 5 percentage points less likely than those without a high school degree in the psid among those withdrawing housing equity in the psid college graduates extract significantly less equity and are less likely to have high levels of housing leverage after doing so

an efficient dynamic auction for heterogeneous commodities this paper proposes a new dynamic design for auctioning multiple heterogeneous commodities generalizing earlier work that treated identical objects an auctioneer wishes to allocate one or more units of each of k heterogeneous commodities to n bidders the auctioneer announces a vector of current prices bidders report back quantities demanded at these prices and the auctioneer adjusts the prices units are credited to bidders at the current prices as their opponents demands decline and the process continues until every commodity market clears bidders rather than being required to behave as price takers are permitted to strategically exercise their market power nevertheless with pure private values the proposed auction yields walrasian equilibrium prices an efficient outcome results as from a vickrey clarke groves mechanism but bidders are only required to evaluate their demands along a one dimensional path of prices rather than reporting their utilities over the entire k dimensional consumption set the auction is also more transparent and potentially simpler for bidders to understand and has the advantage of assuring the privacy of the upper portions of bidders demands theoretically the new auction provides a new foundation for convergence to walrasian equilibrium in an exchange economy practically it provides an efficient method for simultaneously auctioning two or more related types of securities for example three month and six month treasury bills it is also potentially useful for auctioning multiple types of communications spectrum for example licenses for paired and unpaired spectrum

a double track adjustment process for discrete markets with substitutes and complements we propose a new walrasian tatonnement process called a double track procedure for efficiently allocating multiple heterogeneous indivisible items in two distinct sets to many buyers who view items in the same set as substitutes but items across the two sets as complements in each round of the process a walrasian auctioneer first announces the current prices for all items buyers respond by reporting their demands at these prices and then the auctioneer adjusts simultaneously the prices of items in one set upward but those of items in the other set downward it is shown that this procedure converges globally to a walrasian equilibrium in finitely many rounds

the package assignment model we study assignment problems where individuals trade packages consisting of several rather than single objects although buyers reservations values are non additive efficient assignments can be formulated as a linear programming problem in which the pricing functions expressing duality may be non linear in the objects constituting the packages the interconnections among the linear programming formulation walrasian equilibrium and the core are established in the single seller auction version a necessary and sufficient condition is given for the vickrey payoff point to be implementable by a pricing equilibrium journal of economic literature classification numbers c62 d44 d51

on ascending vickrey auctions for heterogeneous objects abstract we construct an ascending auction for heterogeneous objects by applying a primal dual algorithm to a linear program that represents the efficient allocation problem for this setting the auction assigns personalized prices to bundles and asks bidders to report their preferred bundles in each round a bidder s prices are increased when he belongs to a minimally undersupplied set of bidders this concept generalizes the notion of overdemanded sets of objects introduced by demange gale and sotomayor for the one to one assignment problem under a submodularity condition the auction implements the vickrey clarke groves outcome we show that this type of condition is somewhat necessary to do so when classifying the ascending auction literature in terms of their underlying algorithms our auction fills a gap in that literature we relate our results to various ascending auctions in the literature

the economic importance of financial literacy theory and evidence this paper undertakes an assessment of a rapidly growing body of economic research on financial literacy we start with an overview of theoretical research which casts financial knowledge as a form of investment in human capital endogenizing financial knowledge has important implications for welfare as well as policies intended to enhance levels of financial knowledge in the larger population next we draw on recent surveys to establish how much or how little people know and identify the least financially savvy population subgroups this is followed by an examination of the impact of financial literacy on economic decision making in the united states and elsewhere while the literature is still young conclusions may be drawn about the effects and consequences of financial illiteracy and what works to remedy these gaps a final section offers thoughts on what remains to be learned if researchers are to better inform theoretical and empirical models as well as public policy jel a20 d14 g11 i20 j26

an efficient ascending bid auction for multiple objects when bidders exhibit multi unit demands standard auction methods generally yield inefficient outcomes this article proposes a new ascending bid auction for homogeneous goods such as treasury bills or telecommunications spectrum the auctioneer announces a price and bidders respond with quantities items are awarded at the current price whenever they are clinched and the price is incremented until the market clears with private values this dynamic auction yields the same outcome as the sealed bid vickrey auction but has advantages of simplicity and privacy preservation with interdependent values this auction may retain efficiency whereas the vickrey auction suffers from a generalized winner s curse

ascending price vickrey auctions for general valuations ascending price auctions typically involve a single price path with buyers paying their final bid price using this traditional definition no ascending price auction can achieve the vickrey clarke groves vcg outcome for general private valuations in the combinatorial auction setting we relax this definition by allowing discounts to buyers from the final price of the auction or alternatively calculating the discounts dynamically during the auction while still maintaining a single price path using a notion called universal competitive equilibrium prices shown to be necessary and sufficient to achieve the vcg outcome using ascending price auctions we define a broad class of ascending price combinatorial auctions in which truthful bidding by buyers is an ex post nash equilibrium any auction in this class achieves the vcg outcome and ex post efficiency for general valuations we define two specific auctions in this class by generalizing two known auctions in the literature 11 24

an ascending vickrey auction for selling bases of a matroid consider selling bundles of indivisible goods to buyers with concave utilities that are additively separable in money and goods we propose an ascending auction for the case when the seller is constrained to sell bundles whose elements form a basis of a matroid it extends easily to polymatroids applications include scheduling allocation of homogeneous goods and spatially distributed markets among others our ascending auction induces buyers to bid truthfully and returns the economically efficient basis unlike other ascending auctions for this environment ours runs in pseudopolynomial or polynomial time furthermore we prove the impossibility of an ascending auction for nonmatroidal independence set systems

the role of financial literacy in determining retirement plans nber working paper seriesthe role of financial literacy in determining retirement plansrobert clarkmelinda sandler morrillsteven g allenworking paper 16612http www nber org papers w16612national bureau of economic research1050 massachusetts avenuecambridge ma 02138december 2010this research is funded in part by a grant from finra investor education foundation we wouldlike to thank jennifer maki mehtab randhawa and evan rogers for their research assistance theresearch could not have been accomplished without the cooperation of the companies that partneredwith us we would also like to thank nicholas horsewood annamaria lusardi olivia mitchell andtwo anonymous referees for useful comments all remaining errors are our own the views expressedherein are those of the authors and do not necessarily reflect the views of the national bureau of economicresearch finra investor education foundation or any of its affiliated companies 2010 by robert clark melinda sandler morrill and steven g allen all rights reserved shortsections of text not to exceed two paragraphs may be quoted without explicit permission providedthat full credit including notice is given to the source

baby boomer retirement security the roles of planning financial literacy and housing wealth abstract we compare wealth holdings across two cohorts of the health and retirement study the early baby boomers in 2004 and individuals in the same age group in 1992 levels and patterns of total net worth have changed relatively little over time though boomers rely more on housing equity than their predecessors most important planners in both cohorts arrive close to retirement with much higher wealth levels and display higher financial literacy than non planners instrumental variables estimates show that planning behavior can explain the differences in savings and why some people arrive close to retirement with very little or no wealth

effectiveness of employer provided financial information hiring to retiring in order to maximize lifetime utility workers must make choices throughout their careers to plan and save for retirement with the aging of the baby boomers and increasing life expectancies it is more important than ever for individuals to ensure they have adequate savings and resources for retirement to make optimal choices individuals need sufficient knowledge of how both national and employer provided retirement plans work and what benefits they should expect further they must have adequate financial literacy to navigate complex financial instruments and to understand the importance of various plan characteristics traditional models of life cycle earnings and consumption are based on the assumption that workers are aware of investment options understand the benefits they will receive from various retirement plans and have the ability to assess the impact of their saving decisions

the english auction with differentiated commodities abstract we study economies with indivisibilities that satisfy the gross substitutes gs condition we define an excess demand set with the property that increasing the prices of all goods in excess demand eventually leads to the smallest walrasian prices this procedure is a generalization of the auction studied by g demange d gale and m j sotomayor polit econ 94 1986 863 872 in our auction truthful revelation of demand is a perfect bayesian equilibrium if the smallest walrasian prices correspond to the vickrey clarke groves payments however no dynamic auction can reveal sufficient information to implement the vickrey mechanism if all gs preferences are allowed journal of economic literature classification numbers d4 d44 d5 d51

sources of growth in french agriculture since the slowdown in the growth of world agricultural trade in 1980 the united states and the european community ec have engaged in a series of debates over their respective agricultural policies high producer prices and the general absence of production controls in europe have been of particular concern in the united states as world grain stocks have risen and the ec has emerged with substantial subsidies as a net cereals exporter levels of frustration have increased on both sides of the atlantic as the united states has responded with its own export enhancement payments and other costly policies with current positions difficult to sustain the united states and some members of the european community now seek means to limit their conflict and obtain relief from the high costs of their agricultural programs the reduction of grain stocks resulting from the drought affect

competitive equilibrium in an exchange economy with indivisibilities abstract we analyze an exchange economy in which i all commodities except money are indivisible ii agents preferences can be described by a reservation value for each bundle of indivisible objects and iii all agents are price takers we obtain a necessary and sufficient condition under which market clearing prices exist implications for market mechanisms are discussed journal of economic literatureclassification numbers d51 c78

iterative auction design for tree valuations we study a special class of multi item valuations tree valuations that exhibit both value complementarity and substitutability we provide a linear programming formulation of the efficient allocation problem that is of polynomial size in the number of agents and items this reveals a new class of valuations for which a walrasian equilibrium exists in the presence of value complementarities an iterative algorithm for this linear program in conjunction with an appropriate payment rule yields an iterative auction that implements the efficient outcome at an ex post perfect equilibrium this auction relies on a simple pricing rule compact demand reports and uses a novel interleaved price update structure to assign final payments to bidders that guarantee truthful bidding

understanding preferences demand types and the existence of equilibrium with indivisibilities we propose new techniques for understanding agents valuations our classification into demand types incorporates existing definitions substitutes complements strong substitutes etc and permits new ones our unimodularity theorem generalises previous results about when competitive equilibrium exists for any set of agents whose valuations are all of a demand type for indivisible goods contrary to popular belief equilibrium is guaranteed for more classes of purely complements than of purely substitutes preferences our intersection count theorem checks equilibrium existence for combinations of agents with specific valuations by counting the intersection points of geometric objects applications include matching and coalition formation and the product mix auction introduced by the bank of england in response to the financial crisis

productivity and international competitiveness of agriculture in the european union and the united states this study looks at international competitiveness of agriculture in the european union and the united states the most intuitive concept is that of price competitiveness we calculate relative prices for 11 member states of the european union and the united states for the period 1973 2002 we assume that markets are perfectly competitive and in long run equilibrium so that the observed price always equals average total cost as measured by the cost dual to the production function this assumption is used in our calculation of relative competitiveness and productivity gaps between the european union and the united states and in our decomposition of relative price movements between changes in relative input prices and changes in relative productivity levels

what is the cause of growth in regional trade trade liberalisation or rtas the case of agriculture this paper delves into the debate on the proliferation of regional trade arrangements by focusing on bilateral agricultural trade data over the 1962 1995 period for countries that currently are members of nafta mercosur the eu and apec agricultural is chosen because it has historically been protected by developed and dis protected by developing nations while in the case of the eu its common agricultural policy was the major policy jointly managed and funded by member countries we suggest that the literature has tended to focus on factors explaining the level of trade and neglected factors affecting growth in trade while neighborhood characteristics affect neighborhood trade they also appear to affect the policy regimes of neighboring countries the shift to more outward oriented regimes is thus likely to induce a dynamic in trade among neighboring countries requiring several years to stabilize as neighborhood trade grows it is natural to form trade arrangements so as to harmonize policies and to remove other barriers if this is the case then we should expect the growth in intra regional trade to exceed growth in extra regional trade and these patterns should occur before the formation of regional trade arrangements our results support this explanation this abstract was borrowed from another version of this item

equilibria and indivisibilities gross substitutes and complements this paper examines an exchange economy with heterogeneous indivisible objects that can be substitutable or complementary we show that a competitive equilibrium exists in such economies provided that all the objects can be partitioned into two groups and from the viewpoint of each agent objects in the same group are substitutes and objects across the two groups are complements this condition generalizes the well known kelso crawford gross substitutes condition and is called gross substitutes and complements we also provide practical and typical examples from which substitutes and complements are both jointly observed