No Compelling Evidence That Newborns Imitate Oral Gestures

Newborns (N = 83) were presented with 3 conditions, each for 160 sec: tongue protrusion (TP), mouth opening (MO), and control (CO). In TP and MO, a female model alternated between demonstrating the gesture for 20 sec and presenting a passive, motionless face for 20 sec. In CO, she presented a passive face in both the “demonstration” and “passive” intervals. The participants' eyes were more widely open in the demonstration intervals of TP and MO than in the passive intervals, indicating that they were attending to the gestures. In TP, the participants produced more TP responses than MO responses, but in MO there was no effect, undermining the neonatal imitation hypothesis.     

Welfare and Work: Complementary Strategies forLow‐Income Women?

We examine the effects of mothers' strategies of combining employment and welfare receipt during the first 3 years of their child's life on the child's cognitive development, behavior problems, and home learning environment at ages 5 to 6. We compare the child outcomes of those mothers who were continuously employed and received no welfare with (a) those who worked some or all of the 3 years and also received public assistance and (b) those who were totally dependent on public assistance. We studied children in single‐parent families (N= 1271 ) living below 200% of the poverty threshold using data from the National Longitudinal Survey of Youth—Child Supplement. No negative association was found on most child outcomes with a mother's employment whether or not it was combined with public assistance. However, mothers' not working at all and receiving financial support solely from AFDC was associated with negative child outcomes. We discuss the implications of these findings for the possible effects of the new welfare laws on families and young children.     

Perceived Fairness and Compliance With Child Support Obligations

This paper examines whether perceptions of fairness motivate fathers to pay child support and whether perceptions of fairness interact with routine income withholding in collecting payments. Using a study of 392 nonresident fathers who filed for divorce between 1986 and 1988 in the state of Wisconsin, I found that both perceived fairness and income withholding increase fathers' compliance with child support obligations. The effects of these two strategies on compliance are not additive, however. If fathers think their child support orders are fair, the use of routine income withholding does not add to compliance.     

Social and Emotional Functioning of Older Asian American Adolescents

This study identified a constellation of psychosocial problems reported by older Asian American adolescents that was different from their Caucasian peers. When compared to 386 Caucasian American adolescents from the same community, Asian American students performed better academically and reported fewer delinquent behaviors. However, these Asian American youth reported higher levels of depressive symptomatology, withdrawn behavior, and social problems. They also perceived themselves more poorly and were more dissatisfied with their social support. These differences highlight the unique mental health needs of older Asian American youth. Practice recommendations are made that consider traditional Asian values and the role that family members can play in the development of effective treatment plans.     

Projection‐Based Statistical Inference in Linear Structural Models with Possibly Weak Instruments

It is well known that standard asymptotic theory is not applicable or is very unreliable in models with identification problems or weak instruments. One possible way out consists of using a variant of the Anderson–Rubin ((1949), AR) procedure. The latter allows one to build exact tests and confidence sets only for the full vector of the coefficients of the endogenous explanatory variables in a structural equation, but not for individual coefficients. This problem may in principle be overcome by using projection methods (Dufour (1997), Dufour and Jasiak (2001)). At first sight, however, this technique requires the application of costly numerical algorithms. In this paper, we give a general necessary and sufficient condition that allows one to check whether an AR‐type confidence set is bounded. Furthermore, we provide an analytic solution to the problem of building projection‐based confidence sets from AR‐type confidence sets. The latter involves the geometric properties of “quadrics” and can be viewed as an extension of usual confidence intervals and ellipsoids. Only least squares techniques are needed to build the confidence intervals.     

Dynamic Global Games of Regime Change: Learning,Multiplicity, and the Timing of Attacks

Global games of regime change—coordination games of incomplete information in which a status quo is abandoned once a sufficiently large fraction of agents attack it—have been used to study crises phenomena such as currency attacks, bank runs, debt crises, and political change. We extend the static benchmark examined in the literature by allowing agents to take actions in many periods and to learn about the underlying fundamentals over time. We first provide a simple recursive algorithm for the characterization of monotone equilibria. We then show how the interaction of the knowledge that the regime survived past attacks with the arrival of information over time, or with changes in fundamentals, leads to interesting equilibrium properties. First, multiplicity may obtain under the same conditions on exogenous information that guarantee uniqueness in the static benchmark. Second, fundamentals may predict the eventual fate of the regime but not the timing or the number of attacks. Finally, equilibrium dynamics can alternate between phases of tranquility—where no attack is possible—and phases of distress—where a large attack can occur—even without changes in fundamentals.     

Bounds in Competing Risks Models and the War on Cancer

In 1971, President Nixon declared war on cancer. Thirty years later, many declared this war a failure: the age‐adjusted mortality rate from cancer in 2000 was essentially the same as in the early 1970s. Meanwhile the age‐adjusted mortality rate from cardiovascular disease fell dramatically. Since the causes that underlie cancer and cardiovascular disease are likely dependent, the decline in mortality rates from cardiovascular disease may partially explain the lack of progress in cancer mortality. Because competing risks models (used to model mortality from multiple causes) are fundamentally unidentified, it is difficult to estimate cancer trends. We derive bounds for aspects of the underlying distributions without assuming that the underlying risks are independent. We then estimate changes in cancer and cardiovascular mortality since 1970. The bounds for the change in duration until death for either cause are fairly tight and suggest much larger improvements in cancer than previously estimated.     

A WHITER SHADE OF PALE: ON THE POLITICAL ECONOMY OF REGULATORY INSTRUMENTS

We consider an intertemporal policy game between changing governments that differ in their attitudes towards a particular feature of market outcomes, exemplified with environmental pollution. When in power, a government will choose policy instruments and set strictness of regulation with a view to influencing the policy of future, possibly different, governments. We demonstrate that a “brown” government favours emission quotas over effluent taxes, as quotas establish property rights that are costly to reverse. Conversely, a “green” government prefers to regulate by taxes, in order to limit the incentives of future brown governments to ease regulations. Strategic behaviour tends to exaggerate policy differences (making green governments greener and brown governments browner) compared to when such strategic considerations were not an issue. (JEL: D81, D9, H23, L51, Q28, Q38)