the empirical content of the roy model this paper clarifies and extends the classical roy model of self selection and earnings inequality the original roy model based on the assumption that log skills are normally distributed is shown to imply that pursuit of comparative advantage in a free market reduces earnings inequality compared to the earnings distribution that would result if workers were randomly assigned to sectors aggregate log earnings are right skewed even if one sectoral distribution is left skewed most major implications of the log normal roy model survive if differences in skills are log concave however few implications of the model survive if skills are generated from more general distributions we consider the identifiability of the roy model from data on earnings distributions the normal theory version is identifiable without regressors or exclusion restrictions sectoral distributions can be identified knowing only the aggregate earnings distribution for general skill distributions the model is not identified and has no empirical content with sufficient price variation the model can be identified from multimarket data cross sectional variation in regressors can substitute for price variation in restoring empirical content to the roy model

exploring investment potential in a context of nuclear phase out uncertainty perfect vs imperfect electricity markets abstract in view of the ongoing nuclear power debate in europe we analyze how uncertainty about a nuclear phase out affects investment capacity decisions by belgian electricity suppliers depending on the type of market structure considered to achieve this goal we build a structural model and solve it by using game theoretic and optimization approaches in order to consider the different types of market structure namely oligopoly simplified to a duopoly in this case and the two extremes of the competition spectrum i e monopoly and perfect competition we show that higher levels of investment in new electricity generation capacity are reached with decreasing probability of nuclear license extension and or with higher levels of competition in the market moreover investments in perfectly competitive markets are less influenced by changes in the probability of future nuclear license extension resulting in a more stable long term investment climate however the consideration of possible changes in market structure and gradual nuclear phase out is crucial in order to not overestimate investment potential in belgium

the demand for and impact of learning hiv status this paper evaluates an experiment in which individuals in rural malawi were randomly assigned monetary incentives to learn their hiv results after being tested distance to the hiv results centers was also randomly assigned without any incentive 34 percent of the participants learned their hiv results however even the smallest incentive doubled that share using the randomly assigned incentives and distance from results centers as instruments for the knowledge of hiv status sexually active hiv positive individuals who learned their results are three times more likely to purchase condoms two months later than sexually active hiv positive individuals who did not learn their results however hiv positive individuals who learned their results purchase only two additional condoms than those who did not there is no significant effect of learning hiv negative status on the purchase of condoms

instruments randomization and learning about development there is currently much debate about the effectiveness of foreign aid and about what kind of projects can engender economic development there is skepticism about the ability of econometric analysis to resolve these issues or of development agencies to learn from their own experience in response there is increasing use in development economics of randomized controlled trials rcts to accumulate credible knowledge of what works without overreliance on questionable theory or statistical methods when rcts are not possible the proponents of these methods advocate quasirandomization through instrumental variable iv techniques or natural experiments i argue that many of these applications are unlikely to recover quantities that are useful for policy or understanding two key issues are the misunderstanding of exogeneity and the handling of heterogeneity i illustrate from the literature on aid and growth actual randomization faces similar problems as does quasi randomization notwithstanding rhetoric to the contrary i argue that experiments have no special ability to produce more credible knowledge than other methods and that actual experiments are frequently subject to practical problems that undermine any claims to statistical or epistemic superiority i illustrate using prominent experiments in development and elsewhere as with iv methods rct based evaluation of projects without guidance from an understanding of underlying mechanisms is unlikely to lead to scientific progress in the understanding of economic development i welcome recent trends in development experimentation away from the evaluation of projects and toward the evaluation of theoretical mechanisms jel c21 f35 o19

excess capacity as a barrier to entry an empirical appraisal this paper examines excess capacity barriers to entry and investment dynamics in a sample of thirty eight chemical product industries logit and log linear models of investment behavior are estimated and specific case examples are considered the results show that incumbents rarely built excess capacity pre emptively in an effort to deter entry in general entrants and incumbents exhibited similar investment behavior

investment in electricity markets with asymmetric technologies abstract capacity investments in electricity markets is one of the main issues in the restructuring process to ensure competition and enhance system security of networks we study competition between hydro and thermal electricity generators under demand uncertainty producers compete in quantities and each is constrained the thermal generator by capacity and the hydro generator by water availability we analyze a two period game emphasizing the incentives for capacity investments by the thermal generator we characterize both markov perfect and open loop equilibria in the markov perfect equilibrium investment is discontinuous in initial capacity and higher than it is in the open loop equilibrium however since there are two distortions in the model equilibrium investment can be either higher or lower than the efficient investment

coarse thinking and persuasion we present a model of uninformative persuasion in which individuals think coarsely they group situations into categories and apply the same model of inference to all situations within a category coarse thinking exhibits two features that persuaders take advantage of i transference whereby individuals transfer the informational content of a given message from situations in a category where it is useful to those where it is not and ii framing whereby objectively useless information influences individuals choice of category the model sheds light on uninformative advertising and product branding as well as on some otherwise anomalous evidence on mutual fund advertising

imperfect information and dynamic conjectural variations this article analyzes oligopoly interaction in an environment where firms are imperfectly informed about the evolution of the market demand curve the analysis develops a two period cournot framework under the assumptions that demand shifts are positively serially correlated that firms never directly observe the demand curve and that firms never observe the previous quantity decisions of rivals firms do draw inferences about the position of the demand curve from past observations on prices consequently the current output of a firm will influence the current market price which will then influence rivals inferences about future demand the future output decisions of rivals will respond accordingly the theory predicts negative dynamic conjectural variations essentially a firm perceives that an increase in its output will lower the current market clearing price which will cause rival firms to think that the demand curve has shifted down and hence induce them to lower their outputs in the future

selective trials a principal agent approach to randomized controlled experiments we study the design of randomized controlled experiments when outcomes are significantly affected by experimental subjects unobserved effort expenditure while standard randomized controlled trials rcts are internally consistent the unobservability of effort compromises external validity we approach trial design as a principal agent problem and show that natural extensions of rcts which we call selective trials can help improve external validity in particular selective trials can disentangle the effects of treatment effort and the interaction of treatment and effort moreover they can help identify when treatment effects are affected by erroneous beliefs and inappropriate effort expenditure

strategic investment and conjectural variations abstract this paper analyzes investment decisions under the alternative assumptions of competitive collusive open loop non cooperative and feedback non cooperative behavior steady state capital stocks prices and outputs are obtained and compared the paper shows that one of the linear feedback equilibrium decision rule coefficients is a dynamic version of a contemporaneous conjectural variation the same decision rule coefficients are shown to imply a particular value for the contemporaneous conjecture the implied conjecture embodies subgame perfection and approaches the competitive value as the number of firms in the industry increases

on the measurement of capacity utilization capacity utilization is usually defined as the ratio of actual output to the output corresponding to 1 the minimum point on the short run average total cost curve and 2 the point of tangency between the long run average total cost and short run average total cost curves in practice however capacity utilization is often measured as the ratio of actual to the maximum potential output consistent with a given capital stock this paper demonstrates how to estimate the theoretical measures of capacity utilization and examines the correlation between three measures of capacity utilization and the mcgraw hill estimates of capacity utilization using data from a sample of u s privately owned electric utilities for 1961 83 copyright 1989 by blackwell publishing ltd

what matters and what does not in households decision to invest in malaria prevention this paper examines the take up of a new malaria control device by rural households in kenya and tests whether the demand curve for the device varies with the framing of marketing messages and with the gender of the person targeted by the marketing previous research suggests that the demand for malaria prevention is highly price sensitive jessica cohen and dupas 2008 even though the private returns to preventing malaria are very large christian lengeler 2004 in the standard model of investment in human capital individuals invest in a health product if the expected benefits from the product outweigh its costs michael grossman 1972 in this framework the low take up observed at relatively moderate prices by cohen and dupas 2008 could be due to people underestimating the expected benefits of investing in prevention or due to people being credit constrained and unable to pay the cost up front it is also possible that the standard model does not apply because people have time inconsistent preferences or because they are uncertain about their own preferences and rely on external cues to resolve their own uncertainty when they need to make a decision an extensive literature in psychology and marketing suggests that decision making can be affected by frames or cues that do not add information about a product but can be effective at persuading individuals to invest in it for example in a recent field experiment in south africa marianne bertrand et al 2008 found what matters and what does not in households decision to invest in malaria prevention

rational expectations and the paradox of policy relevant natural experiments abstract policy experiments using large microeconomic datasets have recently gained ground in macroeconomics imposing rational expectations we examine robustness of evidence derived from ideal natural experiments applied to atomistic agents in dynamic settings paradoxically once experimental evidence is viewed as sufficiently clean to use it then becomes contaminated by ex post endogeneity measured responses depend upon priors and the objective function into which evidence is fed moreover agents policy beliefs become endogenously correlated with their causal parameters severely clouding inference e g sign reversals and non invertibility may obtain treatment control differences are contaminated for non quadratic adjustment costs constructively we illustrate how inference can be corrected accounting for feedback and highlight factors mitigating contamination

can higher prices stimulate product use evidence from a field experiment in zambia the controversy over how much to charge for health products in the developing world rests in part on whether higher prices can increase use either by targeting distribution to high use households a screening effect or by stimulating use psychologically through a sunk cost effect we develop a methodology for separating these two effects we implement the methodology in a field experiment in zambia using door to door marketing of a home water purification solution we find evidence of economically important screening effects by contrast we find no consistent evidence of sunk cost effects jel c93 d12 i11 m31 o12

modeling technology adoption in developing countries an analysis of technology adoption decisions by poor farmers is provided some possible empirical models for studying technology adoption are reviewed the issue of theoretical consistency is dealt with in terms of the costs of such consistency measured in data needs and model complexity and the benefits measured in terms of understanding the micro economic foundations of adoption

productivity in piece rate labor markets evidence from rural malawi abstract piece rate compensation is a common feature of developing country labor markets but little is known about how piece rate workers respond to incentives or the tradeoffs that an employer faces when setting the terms of the contract in a field experiment in rural malawi we hired casual day laborers at piece rates and collected detailed data on the quantity and quality of their output specifically we use a simplified becker degroot marschak mechanism which provides random variation in piece rates conditional on revealed reservation rates to separately identify the effects of worker selection and incentives on output we find a positive relationship between output quantity and the piece rate and show that this is solely the result of the incentive effect not selection in addition we randomized whether workers were subject to stringent quality monitoring monitoring led to higher quality output at some cost to the quantity produced however workers do not demand higher compensation when monitored and monitoring has no measurable effect on the quality of workers willing to work under a given piece rate together the set of worker responses that we document lead the employer to prefer a contract that offers little surplus to the worker consistent with an equilibrium in which workers have little bargaining power

making the most out of programme evaluations and social experiments accounting for heterogeneity in programme impacts the conventional approach to social programme evaluation focuses on estimating mean impacts of programmes yet many interesting questions regarding the political economy of programmes the distribution of programme benefits and the option values conferred on programme participants require knowledge of the distribution of impacts or features of it this paper presents evidence that heterogeneity in response to programmes is empirically important and that classical probability inequalities are not very informative in producing estimates or bounds on the distribution of programme impacts we explore two methods for supplementing the information in these inequalities based on assumptions about participant decision making processes and about the strength in dependence between outcomes in the participation and non participation states dependence is produced as a consequence of rational choice by participants we test for stochastic rationality among programme participants and present and implement methods for estimating the option values of social programmes

experimental identification of asymmetric information evidence on crop insurance in the philippines abstract i study asymmetric information in crop insurance in the philippines using a two level randomized field experiment and incentivized preference elicitation in this first experimental study of moral hazard in non health insurance preventable damages double on randomly insured plots among farmers with high trust in the insurance provider farmers prefer insurance on plots that are at risk of floods and crop diseases a sign of classic adverse selection and plots that are far away from home a sign of selection on anticipated moral hazard behavior resulting in 72 higher payouts on preferred plots overcoming these challenges requires leveraging new technologies

a theory of dynamic oligopoly iii cournot competition abstract we study the markov perfect equilibrium mpe of an alternating move infinite horizon duopoly model where the strategic variable is quantity we exhibit a pair of difference differential equations that when they exist differentiable mpe strategies satisfy for quadratic payoff functions we solve these equations in closed form and demonstrate that the mpe corresponding to the solution is the limit of the finite horizon equilibrium as the horizon tends to infinity we conclude with a discussion of adjustment costs and endogenization of the timing

crime intimidation and whistleblowing a theory of inference from unverifiable reports we consider a game between a principal an agent and a monitor in which the principal would like to rely on messages by the monitor the potential whistleblower to target intervention against a misbehaving agent the difficulty is that the agent can credibly threaten to retaliate against the monitor in the event of an intervention in this setting intervention policies that are responsive to the monitor s message provide informative signals to the agent which can be used to target threats efficiently principals that are too responsive to information shut down communication channels successful intervention policies must therefore garble the information provided by monitors and cannot be fully responsive we show that policy evaluation on the basis of non verifiable whistleblower messages is feasible under arbitrary incomplete information provided policy design takes into account that messages are endogenous

the illusion of sustainability this brief summarizes the results of a gender impact evaluation study entitled the illusion of sustainability conducted during the time period 1998 to 2001 in kenya the study observed that deworming is a public good since much of its social benefit comes through reduced disease transmission people were less likely to take deworming if their direct first order or indirect second order social contacts were exposed to deworming the introduction of a small fee for deworming drugs led to an 80 percent reduction in treatment rates take up was not sensitive to the exact price level suggesting that it is particularly counter productive to charge small positive prices for the treatment of infectious diseases an intensive school health education had no impact on worm prevention funding for the study derived from world bank nih fogarty international center berkeley center for health research

observing unobservables identifying information asymmetries with a consumer credit field experiment information asymmetries are important in theory but difficult to identify in practice we estimate the presence and importance of hidden information and hidden action problems in a consumer credit market using a new field experiment methodology we randomized 58 000 direct mail offers to former clients of a major south african lender along three dimensions i an initial offer interest rate featured on a direct mail solicitation ii a contract interest rate that was revealed only after a borrower agreed to the initial offer rate and ii a dynamic repayment incentive that was also a surprise and extended preferential pricing on future loans to borrowers who remained in good standing these three randomizations combined with complete knowledge of the lender s information set permit identification of specific types of private information problems our setup distinguishes hidden information effects from selection on the offer rate via unobservable risk and anticipated effort from hidden action effects via moral hazard in effort induced by actual contract terms we find strong evidence of moral hazard and weaker evidence of hidden information problems a rough estimate suggests that perhaps 13 to 21 of default is due to moral hazard asymmetric information thus may help explain the prevalence of credit constraints even in a market that specializes in financing high risk borrowers

incentives work getting teachers to come to school we use a randomized experiment and a structural model to test whether monitoring and financial incentives can reduce teacher absence and increase learning in india in treatment schools teachers attendance was monitored daily using cameras and their salaries were made a nonlinear function of attendance teacher absenteeism in the treatment group fell by 21 percentage points relative to the control group and the children s test scores increased by 0 17 standard deviations we estimate a structural dynamic labor supply model and find that teachers respond strongly to financial incentives our model is used to compute cost minimizing compensation policies jel i21 j31 j45 o15

rational conjectures in the theory of oligopoly abstract the paper employs the notion of rational conjectural equilibrium to remove the arbitrary nature of conjectures about rivals reactions which characterises the traditional non cooperative theory of oligopoly a general definition of these equilibria is given and the concept is then applied to a simple duopoly model the standard models of perfect competition monopoly limit price dominant firms are shown to emerge as special cases of rational conjectural equilibria

heterogeneous treatment effects in impact evaluation abstract it is very important to know how much we can extrapolate from a study s results this paper examines the issue using data from impact evaluations in development

school subsidies for the poor evaluating the mexican progresa poverty program abstract this paper evaluates how the progresa program which provides poor mothers in rural mexico with education grants has affected enrollment poor children who reside in communities randomly selected to participate in the initial phase of the progresa are compared to those who reside in other control communities pre program comparisons check the randomized design and double difference estimators of the program s effect on the treated are calculated by grade and sex probit models are also estimated for the probability that a child is enrolled controlling for additional characteristics of the child their parents local schools and community and for sample attrition to evaluate the sensitivity of the program estimates these estimates of program short run effects on enrollment are extrapolated to the lifetime schooling and the earnings of adults to approximate the internal rate of return on the public schooling subsidies as they increase expected private wages

trade and technological explanations for changes in sectoral labour demand in oecd economies this paper sets out to establish the main determinants of variations in the demand for aggregate labour in manufacturing and service sectors 22 for a cross section of oecd countries 14 a relatively new panel data set is employed in the analysis the oecd s international sectoral data base preliminary analysis revealed that the within sector variation in the wage share dominated overall variation for most countries and time periods a separate dynamic model was thus generated to explain the within sector variation in the wage share this model contained real wages output the capital stock technological change total factor productivity and trade the imports to value added ratio as independent variables in addition the wage level was also interacted with these explanatory variables on the presumption that skill is positively correlated with the level of wages because of the potential for simultaneity bias estimation was conducted by iv and ols the main findings were that the capital stoc

self confirming equilibrium rium path of play thus if a self confirming equilibrium occurs repeatedly no player ever observes play that contradicts his beliefs even though beliefs about play at off path information sets need not be correct we characterize the ways in which self confirming equilibria and nash equilibria can differ and provide conditions under which self con firming equilibria correspond to standard solution concepts nash equilibrium and its refinements describe a situation in which i each player s strategy is a best response to his beliefs about the play of his opponents and ii each player s beliefs about the opponents play are exactly correct we propose a new equilibrium concept self confirming equilibrium that weakens condition ii by requiring only that players beliefs are correct along the equilibrium path of play thus each player may have incorrect beliefs about how his opponents would play in contingencies that do not arise when play follows the equilibrium and moreover the beliefs of different players may be wrong in different ways the concept of self confirming equilibrium is motivated by the idea that noncooperative equilibria should be interpreted as the outcome of a learning process in which players revise their beliefs using their observations of previous play suppose that each time the game is played the players observe the actions chosen by their opponents but that players do not observe the actions their opponents would have played at the information sets that were not reached along the path of play then if a self confirming equilibrium occurs repeatedly no player ever observes play that contradicts his beliefs so the equilibrium is self confirming in the weak sense of not being inconsistent with the evidence by analogy with the literature on the bandit problem e g rothschild 1974 one might expect that a non nash self confirming equilibrium can be the outcome of plausible learning processes this point was made by fudenberg and

the response by the norwegian aluminium industry to changing market structure abstract this paper analyses how changes in market structure have affected the margins measured by the lerner index of norwegian aluminium plants instead of showing the expected negative trend due to increased competition internationally the margins are found to move procyclically around a constant that significantly exceeds zero three explanations for this stability in the levels of the margins are identified a better exploitation of scale economies increased productivity and product specialisation which allows norwegian producer prices to increase more rapidly than the international reference price

how high are rates of return to fertilizer evidence from field experiments in kenya the idea that peasant farmers are rational profit maximizers has been a staple of development economics since theodore schultz 1964 it has also been influential in shaping policy for example agricultural experts have stressed the importance of fertilizer use in raising agricultural yields pointing to impressive results on experimental farms and to huge differences in agricultural productivity across countries with different levels of fertilizer use robert evenson and douglas gollin 2003 historically many countries subsidized fertilizer in response but economists have been skeptical of claims that farmers are leaving money on the table noting that fertilizer may not have the same returns on real world farms as on experimental farms that returns to fertilizer may be low for many farmers even if they are high on average tavneet suri 2007 that fertilizer may require complementary inputs or may be risky many countries have withdrawn or scaled back fertilizer psychology and development theory and experimental evidence

does unmeasured ability explain the wage premium associated with technological change quantile regression analysis by using the quantile regressions of earnings equation we find that the educational wage premium is higher in industries with rapid technological change than in industries with slower technological change at every decile in the distribution of wage residuals the wage premium associated with the technological change is mostly explained by the returns to workers unobserved heterogeneities which are correlated with education rather than the rents of high tech industries

price and advertising signals of product quality we present a signaling model based on ideas of phillip nelson in which both the introductory price and the level of directly uninformative advertising or other dissipative marketing expenditures are choice variables and may be used as signals for the initially unobservable quality of a newly introduced experience good repeat purchases play a crucial role in our model a second focus of the paper is on illustrating an approach to refining the set of equilibria in signalling games with multiple potential signals

optimal information disclosure a sender randomly draws a prospect characterized by its profitability to the sender and its relevance to a receiver the receiver observes only a signal provided by the sender and accepts the prospect if his bayesian inference about the prospect s relevance exceeds his opportunity cost the sender s profits are typically maximized by partial information disclosure whereby the receiver is induced to accept less relevant but more profitable prospects switches by pooling them with more relevant but less profitable ones baits extensions include maximizing a weighted sum of sender profits and receiver surplus and allowing the sender to use monetary incentives

free distribution or cost sharing evidence from a randomized malaria prevention experiment author s cohen jessica dupas pascaline abstract it is often argued that cost sharing charging a subsidized positive price for a health product is necessary to avoid wasting resources on those who will not use or do not need the product we explore this argument through a field experiment in kenya in which we randomized the price at which prenatal clinics could sell long lasting anti malarial insecticide treated nets itns to pregnant women we find no evidence that costsharing reduces wastage on those that will not use the product women who received free itns are not less likely to use them than those who paid subsidized positive prices we also find no evidence that costsharing induces selection of women who need the net more those who pay higher prices appear no sicker than the average prenatal client in the area in terms of measured anemia an important indicator of malaria cost sharing does however considerably dampen demand we find that uptake drops by 75 percent when the price of itns increases from zero to 0 75 i e from 100 to 87 5 percent subsidy the price at which itns are currently sold to pregnant women in kenya we combine our estimates in a cost effectiveness analysis of itn prices on child mortality that incorporates both private and social returns to itn usage overall our results suggest that free distribution of itns could save many more lives than cost sharing programs have achieved so far and given the large positive externality associated with widespread usage of itns it would likely do so at a lesser cost per life saved

short run subsidies and long run adoption of new health products evidence from a field experiment short run subsidies for health products are common in poor countries how do they affect long run adoption a common fear among development practitioners is that one off subsidies may negatively affect long run adoption through reference dependence people might anchor around the subsidized price and be unwilling to pay more for the product later but for experience goods one off subsidies could also boost long run adoption through learning this paper uses data from a two stage randomized pricing experiment in kenya to estimate the relative importance of these effects for a new improved antimalarial bed net reduced form estimates show that a one time subsidy has a positive impact on willingness to pay a year later inherit to separately identify the learning and anchoring effects we estimate a parsimonious experience good model estimation results show a large positive learning effect but no anchoring we black then discuss the types of products and the contexts inherit for which these results may apply

capacity investment preemption and commitment in an infinite horizon model the commitment value of capacity is analyzed in an infinite horizon duopoly model the paper focuses on the role of alternative behavioral assumptions about the ability of firms to commit to investment paths each firm s investment strategy in a feedback nash equilibrium is shown to be a decreasing function of its rival s current capacity this creates an incentive for a firm to expand its capacity to preempt subsequent rival investment in a precommitment equilibrium there are no incentives to invest preemptively as a consequence steady state capacity levels are greater in a feedback nash equilibrium than in a precommitment equilibrium copyright 1987 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

better late than nothing some comments on deaton 2009 and heckman and urzua 2009 two recent papers deaton 2009 and heckman and urzua 2009 argue against what they see as an excessive and inappropriate use of experimental and quasi experimental methods in empirical work in economics in the last decade they specifically question the increased use of instrumental variables and natural experiments in labor economics and of randomized experiments in development economics in these comments i will make the case that this move towards shoring up the internal validity of estimates and towards clarifying the description of the population these estimates are relevant for has been important and beneficial in increasing the credibility of empirical work in economics i also address some other concerns raised by the deaton and heckman urzua papers

dynamic oligopoly with capacity adjustment costs abstract the literature on strategic investment emphasized the case of completely irreversible investment this paper considers an oligopoly model in which investment is reversible and capacity is subject to adjustment costs an n player linear quadratic differential game is analyzed existence and characterization results for perfect equilibrium feedback strategies are provided feedback strategies provide incentives for each player to invest strategically so as to preempt subsequent expansion by rivals a larger set of perfect equilibria is constructed by using memory dependent trigger strategies equilibria of this type are shown to support joint value maximization for some initial states and asymmetric steady states

making corruption harder asymmetric information collusion and crime we model criminal investigation as a principal agent monitor problem in which the agent can bribe the monitor to destroy evidence building on insights from laffont and martimort s 1997 paper we s

tying odysseus to the mast evidence from a commitment savings product in the philippines we designed a commitment savings product for a philippine bank and implemented it using a randomized control methodology the savings product was intended for individuals who want to commit now to restrict access to their savings and who were sophisticated enough to engage in such a mechanism we conducted a baseline survey on 1777 existing or former clients of a bank one month later we offered the commitment product to a randomly chosen subset of 710 clients 202 28 4 percent accepted the offer and opened the account in the baseline survey we asked hypothetical time discounting questions women who exhibited a lower discount rate for future relative to current trade offs and hence potentially have a preference for commitment were indeed significantly more likely to open the commitment savings account after twelve months average savings balances increased by 81 percentage points for those clients assigned to the treatment group relative to those assigned to the control group we conclude that the savings response represents a lasting change in savings and not merely a short term response to a new product

vouchers for private schooling in colombia evidence from a randomized natural experiment colombia used lotteries to distribute vouchers which partially covered the cost of private secondary school for students who maintained satisfactory academic progress three years after the lotteries winners were about 10 percentage points more likely to have finished 8th grade primarily because they were less likely to repeat grades and scored 0 2 standard deviations higher on achievement tests there is some evidence that winners worked less than losers and were less likely to marry or cohabit as teenagers benefits to participants likely exceeded the 24 per winner additional cost to the government of supplying vouchers instead of public school places

identifying a dominant firm s market power among sellers of a homogeneous product an application to alcoa this paper measures the extent of alcoa s dominant firm market power in the post war us aluminium industry an indirect procedure that combines estimation of the fringe supply elasticity market demand elasticity and extant market share data generates the estimate of alcoa s residual demand elasticity which infers the firm s market power results show that alcoa s market power declines with fringe s expansion