{"title":"Machine learning who to nudge: Causal vs predictive targeting in a field experiment on student financial aid renewal","authors":"Susan Athey , Niall Keleher , Jann Spiess","doi":"10.1016/j.jeconom.2024.105945","DOIUrl":"10.1016/j.jeconom.2024.105945","url":null,"abstract":"<div><div>In many settings, interventions may be more effective for some individuals than for others, so that targeting interventions may be beneficial. We analyze the value of targeting in the context of a large-scale field experiment with over 53,000 college students, where the goal was to use “nudges” to encourage students to renew their financial-aid applications before a non-binding deadline. We begin with baseline approaches to targeting. First, we target based on a causal forest that assigns students to treatment according to those estimated to have the highest treatment effects. Next, we evaluate two alternative targeting policies, one targeting students with low predicted probability of renewing financial aid in the absence of the treatment, the other targeting those with high probability. The predicted baseline outcome is not the ideal criterion for targeting, nor is it a priori clear whether to prioritize low, high, or intermediate predicted probability. Nonetheless, targeting on low baseline outcomes is common in practice, for example when treatment effects are difficult to estimate. We propose hybrid approaches that incorporate the strengths of predictive approaches (accurate estimation) and causal approaches (correct criterion). We show that targeting <em>intermediate</em> baseline outcomes is most effective in our application, while targeting based on low baseline outcomes is detrimental. In one year of the experiment, nudging all students improved early filing by an average of 6.4 percentage points over a baseline average of 37%, and we estimate that targeting half of the students using our preferred policy attains around 75% of this benefit.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 105945"},"PeriodicalIF":9.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Javier Alejo , Antonio F. Galvao , Julian Martinez-Iriarte , Gabriel Montes-Rojas
{"title":"Unconditional quantile partial effects via conditional quantile regression","authors":"Javier Alejo , Antonio F. Galvao , Julian Martinez-Iriarte , Gabriel Montes-Rojas","doi":"10.1016/j.jeconom.2024.105678","DOIUrl":"10.1016/j.jeconom.2024.105678","url":null,"abstract":"<div><div>This paper develops a semi-parametric procedure for estimation of unconditional quantile<span><span> partial effects using quantile regression coefficients. The estimator is based on an identification result showing that, for continuous covariates, unconditional quantile effects are a weighted average of conditional ones at particular quantile levels that depend on the covariates. We propose a two-step estimator for the unconditional effects where in the first step one estimates a structural quantile regression model, and in the second step a nonparametric regression is applied to the first step coefficients. We establish the </span>asymptotic properties of the estimator, say consistency and asymptotic normality. Monte Carlo simulations show numerical evidence that the estimator has very good finite sample performance and is robust to the selection of bandwidth and kernel. To illustrate the proposed method, we study the canonical application of the Engel’s curve, i.e. food expenditures as a share of income.</span></div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 105678"},"PeriodicalIF":9.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139678145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Cross-sectional dependence in idiosyncratic volatility","authors":"Ilze Kalnina , Kokouvi Tewou","doi":"10.1016/j.jeconom.2025.106003","DOIUrl":"10.1016/j.jeconom.2025.106003","url":null,"abstract":"<div><div>This paper introduces an econometric framework for analyzing cross-sectional dependence in the idiosyncratic volatilities of assets using high frequency data. We first consider the estimation of standard measures of dependence in the idiosyncratic volatilities such as covariances and correlations. Naive estimators of these measures are biased due to the use of the error-laden estimates of idiosyncratic volatilities. We provide bias-corrected estimators and the relevant asymptotic theory. Next, we introduce an idiosyncratic volatility factor model, in which we decompose the variation in idiosyncratic volatilities into two parts: the variation related to the systematic factors such as the market volatility, and the residual variation. Again, naive estimators of the decomposition are biased, and we provide bias-corrected estimators. We also provide the asymptotic theory that allows us to test whether the residual (non-systematic) components of the idiosyncratic volatilities exhibit cross-sectional dependence. We apply our methodology to the S&P 100 index constituents, and document strong cross-sectional dependence in their idiosyncratic volatilities. We consider two different sets of idiosyncratic volatility factors, and find that neither can fully account for the cross-sectional dependence in idiosyncratic volatilities. For each model, we map out the network of dependencies in residual (non-systematic) idiosyncratic volatilities across all stocks.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 106003"},"PeriodicalIF":9.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143907645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Limit theory for local polynomial estimation of functional coefficient models with possibly integrated regressors","authors":"Ying Wang , Peter C.B. Phillips","doi":"10.1016/j.jeconom.2025.106007","DOIUrl":"10.1016/j.jeconom.2025.106007","url":null,"abstract":"<div><div>Limit theory for functional coefficient cointegrating regression was recently found to be considerably more complex than earlier understood. The issues were explained and correct limit theory derived for the kernel weighted local level estimator in Phillips and Wang (2023b). The present paper provides complete limit theory for the general kernel weighted local <span><math><mi>p</mi></math></span>th order polynomial estimators of the functional coefficient and the coefficient derivatives. Both stationary and nonstationary regressors are allowed. Implications for bandwidth selection are discussed. An adaptive procedure to select the fit order <span><math><mi>p</mi></math></span> is proposed and found to work well. A robust <span><math><mi>t</mi></math></span>-ratio is constructed following the new limit theory, which corrects and improves the usual <span><math><mi>t</mi></math></span>-ratio in the literature. The robust <span><math><mi>t</mi></math></span>-ratio is valid and works well regardless of the properties of the regressors, thereby providing a unified procedure to compute the <span><math><mi>t</mi></math></span>-ratio and facilitating practical inference. Testing constancy of the functional coefficient is also considered. Finite sample studies are provided that corroborate the new asymptotic theory.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 106007"},"PeriodicalIF":9.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Central bank communication on social media: What, to whom, and how?","authors":"Yuriy Gorodnichenko , Tho Pham , Oleksandr Talavera","doi":"10.1016/j.jeconom.2024.105869","DOIUrl":"10.1016/j.jeconom.2024.105869","url":null,"abstract":"<div><h3>This study answers three questions about central bank communication on Twitter</h3><div>: what was communicated, who were listeners, and how they reacted. Using various natural language processing techniques, we identify the main topics discussed by the Fed and major audiences. While the Fed tweets talking about central banking topics attract greater attention from Twitter users, only the extensive margin is economically meaningful. Among all groups of users, the media accounts and economists are most active in engaging with the Fed, especially when discussing central banking-related issues. We also show that information extracted from the tweets can provide a real-time, qualitative diagnostic for inflation expectations and some reaction of these Twitter-based inflation expectations to policy action and communication.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 105869"},"PeriodicalIF":9.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Paying over the odds at the end of the fiscal year. Evidence from Ukraine","authors":"Margaryta Klymak , Stuart Baumann","doi":"10.1016/j.jeconom.2024.105903","DOIUrl":"10.1016/j.jeconom.2024.105903","url":null,"abstract":"<div><div>Governments are the largest buyers in most countries. They tend to operate annually expiring budgets and spend disproportionately large amounts at year-end. This paper is the first to investigate whether supplier firms increase prices at year-end to benefit from this behaviour. We develop a novel method using neural networks to estimate firms margins from the bidding behaviour of other firms in procurement auctions. We use a dataset of Ukrainian government procurement between 2017 and 2021 to document significantly higher prices and supplier profit margins at year-end. We demonstrate how results change depending on the type of good, the length of the buyer–supplier relationship, and the impact of Covid-19. Finally, we provide policy suggestions on how funds could be saved.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 105903"},"PeriodicalIF":9.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144067959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Estimating coefficient-by-coefficient breaks in panel data models","authors":"Yousef Kaddoura","doi":"10.1016/j.jeconom.2025.106005","DOIUrl":"10.1016/j.jeconom.2025.106005","url":null,"abstract":"<div><div>When estimating structural breaks, existing econometric methods adopt an a approach in which either all parameters change simultaneously, or they remain the same. In this paper, we consider the estimation of panel data models when an unknown subset of coefficients is subject to breaks. The challenge lies in estimating the breaks for each coefficient. To tackle this, we propose a new estimator for panel data, the “Coefficient-by-Coefficient Lasso” break estimator. This estimator is derived by penalizing the coefficients with a fused penalty and using component-wise adaptive weights. We present this estimator for two scenarios: those with homogeneous breaks and those with heterogeneous breaks. We show that the method identifies the number and dates of breaks for all coefficients with high probability and that the post-selection estimator is asymptotically normal. We examine the small-sample properties of the method through a Monte Carlo study and further apply it to analyze the influence of socioeconomic factors on crime.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 106005"},"PeriodicalIF":9.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863355","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Subjective expectations and demand for contraception","authors":"Grant Miller , Áureo de Paula , Christine Valente","doi":"10.1016/j.jeconom.2025.105997","DOIUrl":"10.1016/j.jeconom.2025.105997","url":null,"abstract":"<div><div>One-quarter of married, fertile-age women in Sub-Saharan Africa report not wanting a pregnancy and yet do not practice contraception. We collect detailed data on the subjective beliefs of married, adult women not wanting a pregnancy and estimate a structural model of contraceptive choices. Both our structural model and a validation exercise using an exogenous shock to beliefs show that correcting women’s beliefs about pregnancy risk absent contraception can increase use considerably. Our structural estimates further indicate that costly interventions like eliminating supply constraints would only modestly increase contraceptive use, while confirming the importance of partners’ preferences highlighted in related literature.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 105997"},"PeriodicalIF":9.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Matei Demetrescu , Paulo M.M. Rodrigues , A.M. Robert Taylor
{"title":"Predictive quantile regressions with persistent and heteroskedastic predictors: A powerful 2SLS testing approach","authors":"Matei Demetrescu , Paulo M.M. Rodrigues , A.M. Robert Taylor","doi":"10.1016/j.jeconom.2025.106002","DOIUrl":"10.1016/j.jeconom.2025.106002","url":null,"abstract":"<div><div>We develop new tests for predictability at a given quantile, based on the Lagrange Multiplier [LM] principle, in the context of quantile regression [QR] models which allow for persistent and endogenous predictors driven by heteroskedastic errors. Of the extant predictive QR tests in the literature, only the moving blocks bootstrap implementation, due to Fan and Lee (2019) , of the Wald-type test of Lee (2016) can allow for conditionally heteroskedastic errors in the context of a QR model with persistent predictors. In common with all other tests in the literature these tests cannot, however, allow for unconditionally heteroskedastic behaviour in the errors. The LM-based approach we adopt in this paper is obtained from a simple auxiliary linear test regression which facilitates inference based on established instrumental variable methods. We demonstrate that, as a result, the tests we develop, based on either conventional or heteroskedasticity-consistent standard errors in the auxiliary regression, are robust under the null hypothesis of no predictability to conditional heteroskedasticity and to unconditional heteroskedasticity in the errors driving the predictors, with no need for bootstrap implementation. We also propose tests for joint predictability across a set of multiple distinct quantiles. Simulation results for both conditionally and unconditionally heteroskedastic errors highlight the superior finite sample properties of our proposed LM tests over the tests of Lee (2016) and Fan and Lee (2019) and the recent variable addition tests of Cai et al. (2023). An empirical application to the equity premium for the S&P 500 highlights the practical usefulness of our proposed tests, uncovering significant evidence of predictability in the left and right tails of the returns distribution for a number of predictors containing information on market or firm risk.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 106002"},"PeriodicalIF":9.9,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143839606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Maria Grazia Pittau , Pier Luigi Conti , Roberto Zelli
{"title":"Inference for deprivation profiles in a binary setting","authors":"Maria Grazia Pittau , Pier Luigi Conti , Roberto Zelli","doi":"10.1016/j.jeconom.2025.106000","DOIUrl":"10.1016/j.jeconom.2025.106000","url":null,"abstract":"<div><div>The paper addresses the issue of comparing deprivation distributions when the severity of deprivation is measured by a sum of (weighted) binary variables. To accomplish this task, it provides a graphical tool, the Three I’s of Deprivation (TID) curve, which summarises the incidence, intensity and inequality aspects of deprivation in a society and is the natural counterpart to the TIP curve widely used in income poverty analysis. Uncertainty around the estimated deprivation curves is assessed by simultaneous confidence bands. A dominance hypothesis test is presented to facilitate the comparison and ordering of TID curves across groups and over time. A rank-dependent multi-deprivation index consistent with the TID ordering is calculated and confidence intervals are developed. As a substantive illustration, the evolution of material and social deprivation across European countries over the period of the pandemic outbreak is analysed.</div></div>","PeriodicalId":15629,"journal":{"name":"Journal of Econometrics","volume":"249 ","pages":"Article 106000"},"PeriodicalIF":9.9,"publicationDate":"2025-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143816507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"经济学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}