There has been a sharp rise in labor force participation of married women andespecially women with young children between the 1970s and 1990s in the UnitedStates. Over the same period, cyclical and secular properties of fertility have changedsignificantly. In particular, I document that fertility rate is strongly countercyclicalin the 1960s and 1970s and procyclical thereafter. In addition, women have post-poned childbearing substantially. Using a life-cycle incomplete markets model withaggregate and idiosyncratic uncertainty, I show that cyclical properties and timingof fertility are related to labor force participation decisions of married women. Themodel calibrated to 1960s and 1970s generates countercyclical fertility. A number ofexplanations have been proposed to account for the increase in female labor supply, inparticular a decrease in gender wage gap, an increase in womens returns to experienceand a decrease in child care cost. I introduce these changes into the calibrated modeland evaluate the implications for female labor force participation and properties offertility. I find that each of them separately and all combined can explain some butnot all features of the data. Taking into account the flattening of life-cycle earningsprofile for males helps to account for the data but a significant discrepancy remains.

The goal of federal food and nutrition programs in the United States is to improve the nutritional well-being and health of low income families. A large body of literature evaluates the extent to which the Supplemental Program for Women Infants and Children (WIC) has accomplished this goal, but most studies have been based on research designs that compare program participants to non-participants. If selection into these programs is non-random then such comparisons will lead to biased estimates of the programs true effects. In this study we use the rollout of the WIC program across counties to estimate the impact of the program on infant health. We find that the implementation of WIC lead to an increase in average birthweight and a decrease in the fraction of births that are classified as low birthweight. We find no evidence that these estimates are driven by changes in fertility. Back-of-the-envelope calculations suggest that the initiation of WIC lead to a ten percent increase in the birthweight of infants born to participating mothers.

The inter-racial marriage gap that opened in the past 50 years is generally attributed to a decline in the availability of young black marriageable men. We contend that the associated shortage of desirable men in the marriage market provides those black men who are sought after with the opportunity to attain a high status spouse, which has placed a premium on black women with lighter skin. We provide evidence, based on data drawn from the Multi City Study of Urban Inequality, consistent with this hypothesis. Our theoretical analysis of the marriage market reveals that marriage promotion policies to increase the desire to marry on the part of young black women will serve to exacerbate the importance attached to skin shade.

This paper examines how inows of immigrant students and immigrant labor a ect the post-secondary enrollment of natives. Existing studies have focused on the e ect of increased immi-grant demand for schooling in the education market on native enrollment. However, such analysisomits the e ect that changes in immigrant labor supply in the labor market also have on pricesrelevant to native enrollment decisions. I propose, in a uni ed framework, that immigration-induced price movements in both education and labor markets that change the private returnto higher education are mechanisms that can motivate native enrollment responses. Using U.S.Census microdata from 1970 to 2000, I estimate the causal impact of heterogeneous immigrantinows into local markets on the rate of native college enrollment in those areas. To isolate theexogenous component of immigrant inows from endogenous ows that vary with unobservedmovements in labor demand and college supply, I utilize a logit model of immigrant college de-mand combined with two-stage least squares estimation that exploits geographic variation inhistorical immigrant enclaves. I nd that a 1 percent increase in relatively unskilled immigrantlabor raises the rate of native college enrollment by 0.33 percent, while a 1 percent increase inimmigrant college students does not signi cantly lower enrollment. The positive, crowd-in e ectof immigrant labor inows is driven primarily by natives ages 18-24, consistent with younger na-tives having college demand that is more sensitive to returns than the demand of older natives.The results imply that the rise in the average college enrollment rate of young natives between1970 and 2000 would have been 18 percentage points higher if the skill composition of immigrantlabor inows had remained constant over this period. With the identi cation of a crowd-in e ectand, contrary to prior studies, the lack of a signi cant crowd-out e ect, these ndings provideevidence on how immigrants impact market prices and how natives respond to immigration.

Polycentricity is often conceived to be the product of a long process of very extendeddecentralization from big central cities to adjacent smaller ones, old and new (Hall andPain, 2006: 3). Accordingly, polycentric spatial development (as a process) is usuallyidentified with a development towards a more balanced distribution of functions andactivities across regional space, and with the moderation of intra-regional urban hierarchies.However, the term polycentricity is also linked to the idea that formerly independent, butclose-by and welllinked cities start to fuse into larger metropolitan areas as their spheresof influence start to interfere. Classic products of this kind of polycentric spatialdevelopment can be found in Europe (e.g. the Randstad), but also in the U.S. such areashave been identified (e.g. SF bay Area, Dallas-Fort Worth, Baltimore-Washington, Raleigh-Durham etc). While fusion-mode and decentralization-mode metropolitan areas aresubject to grossly similar overarching trends such as globalization and the postindustrializationand informationalization of the economy, these trends seem to producecontrasting patterns of spatial organization. The dominant trend in fusion-mode polycentricmetropolitan areas appears to be towards the creation of new leading cities and astrengthening rather than a moderation of intra-regional hierarchies. In this paper, weexplore this trend for fusion-mode polycentric metropolitan areas in the U.S., therebyemploying occupational data, and seek to explain the emerging new intra-regionalhierarchies found.

The local average treatment effect (LATE) may differ from the average treatment effect (ATE) when those influenced by the instrument are not representative of the overall population. Heterogeneity in treatment effects may imply that parameter estimates from 2SLS are uninformative regarding the average treatment effect, motivating a search for instruments that affect a larger share of the population. In this paper, I present and estimate a model of home production with heterogeneous costs and benefits to fertility. The results indicate that a sex-preference instrument in Taiwan produces IV estimates closer to the estimated ATE than in the United States, where sex preference is weaker.

We explore the interaction of inter-city and intra-city wage differentials by occupation. The paper makes twomain contributions. 1) We construct an occupation-specific index of workplace centralization that accountsfor the difference between average employment density from the perspective of employees in eachoccupation and average employment density from the perspective of all employees. 2) We provide empiricalevidence that relative wages of central to non-central occupations increase with city size, or equivalently, theelasticity of wages with respect to city size increases with occupational centrality. We conjecture that thisempirical regularity arises because, as city size increases, workers in more central occupations face anincreasingly less desirable locus of housing prices and commuting times relative to workers who have jobs inresidential areas. The results are robust to the inclusion of individual-specific human capital variables andcity-specific fixed effects.

We develop a simple semiparametric framework for combining censored and uncensored samples so that the resulting estimators are consistent, asymptotically normal, and use all information optimally. No nonparametric smoothing is required to implement our estimators. To illustrate our results in an empirical setting, we show how to estimate the effect of changes in compulsory schooling laws on age at first marriage, a variable that is censored for younger individuals. Results from a small simulation experiment suggest that the estimator proposed in this paper can work very well in finite samples.

Workers in high-tech cities earn raw wages that are on average 17% higher than wages of workers in other cities. Using a large sample from the 5% PUMS of the 2000 Census of Population, this paper presents econometric evidence of a tech-city wage premium of approximately 4.6% that is not the result of higher-ability people self-selecting to live in high-tech cities, but rather the result of high-tech cities actually making workers more productive. Although knowledge spillovers are difficult to assess, we use the concepts of the new economic geography and evidence from empirical studies of high-technology regions, such as Silicon Valley and Austin, Texas, to support the view that workers who live in high-tech cities might be more productive because they benefit from a larger supply of knowledge spillovers than workers who live in low-tech cities.

Three parallel implementations of a divide‐and‐conquer search algorithm (called SUDA2) for finding minimal unique itemsets (MUIs) are compared in this paper. The identification of MUIs is used by national statistics agencies for statistical disclosure assessment. The first parallel implementation adapts SUDA2 to a symmetric multi‐processor cluster using the message passing interface (MPI), which we call an MPI cluster; the second optimizes the code for the Cray MTA2 (a shared‐memory, multi‐threaded architecture) and the third uses a heterogeneous ‘group’ of workstations connected by LAN. Each implementation considers the parallel structure of SUDA2, and how the subsearch computation times and sequence of subsearches affect load balancing. All three approaches scale with the number of processors, enabling SUDA2 to handle larger problems than before. For example, the MPI implementation is able to achieve nearly two orders of magnitude improvement with 132 processors. Performance results are given for a number of data sets.

This book is about the migration of West African women to the United States. It recognizes the importance of previous theoretical paradigms (such as the push-pull model of migration and the world systems perspective), but also goes beyond these approaches by incorporating aspects of nationality, culture, normative systems, and the institutional processes that immigrants forge to anchor their immigrant experiences and lived realities in the host society. The aim is to portray the social, economic, and cultural processes by which the women create and give meanings and contents to their diaspora experiences in the United States.

Does immigration affect foreign direct investment? This question has been examined in some form or another since Lucas' (1990) observation that labor and capital do not flow in opposite directions as predicted by economic theory. Existing studies on immigration and FDI have all looked at aggregate flows at the national level, arguing that immigrant networks lower the risk of foreign investment through increased information flows and a built in market. However, these national level studies suffer from identification problems since many of the factors that attract immigrants also attract FDI. This study improves upon identification by looking at the regional distribution of both FDI and immigration from 10 source countries to the 50 U.S. States. Using a unique measure of immigrant network size in each state, I find that immigration is not only positively correlated with FDI, it tends to lead it as well. Comparing a state with an average sized immigrant network to one with a network twice as large, I estimate that the stronger network state will get on average 20 more new foreign-owned affiliates opening up per year, an effect that is quite persistent over time. On average, more skilled immigrant communities attract more FDI, while the pull effect of immigration on FDI also increases with immigrant ties to native countries and with immigrant influence in local communities. These results suggest that immigration creates a positive externality in foreign investment that must be considered when assessing the costs and benefits of labor mobility.

This paper investigates gender differences in economic mobility. In a sample ofmarried couples constructed from the Panel Study of Income Dynamics (PSID), I findthat the intergenerational elasticity of earnings for daughters is significantly lower thanfor sons. I ask whether this gap can be explained by three inter-related mechanisms:parental investments in human capital, positive assortative matching of spouses, andlabor supply responses of married women to their husbands earnings. I develop adynamic general equilibrium model with parental investments to evaluate the relativecontribution of the proposed mechanisms. The parameters are estimated using themethod of simulated moments. My results show that labor supply responses explainabout 83% of the gender gap. They also suggest that parental investments are highlyinfluenced by marriage market conditions, and that this influence is much stronger fordaughters than for sons. As a consequence, the average human capital of men andwomen in the steady state would be reduced by 16% and 45% respectively if humancapital investments did not affect spouses characteristics.

Inferences about earnings volatility across groups and time depend on the underlying models of earnings dynamics, data sources, earnings concepts, and sampling strategies. In this paper we evaluate a model of earnings dynamics in which the permanence of shocks varies by age and education. This specification is consistent with observed earnings changes in administrative panel data, and also with the variance of earnings levels in multiple cross-section (synthetic panel) data. However, expanding the earnings concept to include self-employment and changing sampling strategy to include observations with minimal labor force attachment has first-order effects, and may help explain why some studies conclude that earnings volatility is rising.

This dissertation consist of three separate papers that address the a) the fertility contribution of Mexican-born immigrants to the future U.S. population, b) the impact of immigrants on high U.S. TFR and c) the use of vital rates to estimate the size of the Mexican-born female population in the U.S. In the first paper a new method is proposed to project the contribution of immigration to a receiving country's population that obviates the need to project the number of immigrants by using the full sending-country birth cohort as the risk group to project their receiving-country childbearing. The new method is found to perform dramatically better than conventional methods when projecting to 1999 from selected base years in the past. Projecting forward from 1999, the research estimated the cumulative contribution of Mexican immigrant fertility from the 1980s to 2040 of 36 million births, including 25% to 50% more births after 1995 than are projected using conventional methods. The second paper consists of a decomposition analysis of the recent U.S. TFR into fertility and composition effects of Mexican-born and other foreign-born immigrants. The results show that 6% of the U.S. TFR is attributable to a higher ASFR of immigrant women. About 63% of the foreign-born effect in 1990 and 71% in 2000 is attributable to Mexican-born woman. Approximately 11% of the Mexican-born contribution to the TFR is due to an age composition of the Mexicanborn that favors the high-ASFR ages. The large increase in the size of the foreign-born population in the U.S. from 1990–2000 is mostly offset by reduced TFR of both the foreign-born and the native-born population. Finally the dissertation explores the usability of vital rates in combination with registered number of vital events to estimate the Mexican-born population in the U.S. The results show that the intuitively simple and mathematically sound method is unsuitable for population estimates when mortality rates are bias and sampling error reduces the preciseness of fertility rates.

A relaxation of radio station ownership caps in 1996 induced a wave ofmergers and acquisitions. This paper develops a \two-sided market" em-pirical model of the commercial radio industry to analyze the e ects of thechange in market structure. In the model, both listener and advertiser pref-erences a ect one another via the advertising and programming strategies ofbroadcasters, and audience demographics impact both listener and advertiserdemand. Structural parameter estimates and counter-factual experiments re-veal modest increases in audience welfare and advertising with consolidation.Firms bene t from increased market power by increasing advertising time inless segmented radio markets and, likewise, decreasing advertising in moresegmented markets.

The initial occupational placements of male immigrantsin the U.S. labor market vary significantly by countryof origin even when education and other factors aretaken into account. Does the heterogeneity persistover time? Using data from the 1980, 1990, and 2000U.S. Censuses, this study finds that the performance ofmigrants from countries with lower initial occupational placement levels improves at a higher rate compared withthat of migrants originating from countries with higherinitial levels. Nevertheless, the magnitude of convergencesuggests full catch-up is unlikely. Country specificattributes are found to have less direct impact on the rateof assimilation than on the initial performance.