Se is particularly necessary in infants because of their rapid physical growth period in addition to being indispensable for neurodevelopment. Severe deficiency can lead to cardiomyopathy, hypothyroidism and faltering growth. However, Se can be toxic at high doses. In the paediatric age group, plasma/serum and erythrocyte Se levels seem to increase with age, except in the first year of life. Understanding the variability in Se status during this period can help to identify infants at risk of deficiency and develop strategies for controlling and preventing its consequences. This review aimed to identify the extent and characteristics of the variability of Se status during the first year of life. A search was conducted across five databases to find articles published until 30 July 2024, with no limitations on the language or date of publication. Articles were screened, data were extracted independently by two reviewers, and any disagreement was resolved by a third reviewer. A total of 22 studies comprising 1288 participants were included in this review, 21 of which assessed plasma/serum Se and 12 assessed erythrocyte Se. In the first 4 months of age, serum/plasma Se decreased, remained stable or increased depending on feeding, with an increase in supplemented formula-fed infants and breastfed infants of supplemented mothers. Erythrocyte Se levels showed a declining trend, except in infants fed supplemented formula or breastfed by supplemented mothers. Variability of serum/plasma and erythrocyte Se levels in the first year was associated with maternal Se intake/supplementation and the Se content of the infant’s diet.

Firms become more efficient at innovation activities when they face pressure to meet earnings per share (EPS) targets using stock repurchases. Using a regression-discontinuity framework, we find that incentives to engage in “EPS-motivated buybacks” are followed by more citations and higher values for firms’ new patents. We trace these effects to improved allocation of R&D resources and a greater focus on novel innovation. The positive effects are concentrated among ex ante “innovation-efficient” firms that achieve better patenting outcomes after reorganizing (but not cutting) their R&D investments. Our findings illustrate that short-term earnings pressure can act through a free cash flow channel that motivates more efficient spending.

Firms can become less innovative following a sudden cash “inflow.” Specifically, multinational firms that were eligible to repatriate (and indeed repatriated) cash to the United States under the American Jobs Creation Act (AJCA) generate less valuable patents than otherwise similar firms. They also explore more. This effect only exists among firms in less competitive industries, firms with lower institutional ownership (IO), and firms with overconfident chief executive officers (CEOs); this effect is mainly driven by the reduction in the value of U.S.-originated patents. Our evidence suggests that, without appropriate governance, a cash windfall may lead managers to engage in riskier innovation strategy, which can destroy value.

Ample evidence points to a negative relation between internal funds (profitability) and the demand for external funds (debt issuance). This relation has been interpreted as evidence supporting the pecking order theory. We show, however, that the negative effect of internal funds on the demand for external financing is concentrated among firms that are least likely to face high external financing costs (firms that distribute large amounts of dividends, that are large, and whose debt is rated). For firms on the other end of the spectrum (low payout, small, and unrated), external financing is insensitive to internal funds. These cross-firm differences hold separately for debt and equity, and they are magnified in the aftermath of macroeconomic movements that tighten financing constraints. We argue that the greater complementarity between internal funds and external financing for constrained firms is a consequence of the interdependence of their financing and investment decisions.