We study how parenthood affects gender differences in personal financial behavior using comprehensive, high-frequency bank data covering roughly one third of the adult population in Iceland. Exploiting sharp changes around the birth of the first child in an event-study framework, we show that parenthood generates large and persistent financial child penalties for women. At childbirth, women sharply reduce savings, draw down private pension balances, increase reliance on consumer credit, and disengage from risky asset markets, while men show no comparable response. These effects persist for over two decades after the first birth. To assess whether these patterns are mechanically driven by income losses associated with parental leave, we decompose financial responses into components implied by income changes and behavioral adjustments conditional on income. Income-based mechanical effects explain essentially none of the observed responses; the financial child penalties are driven overwhelmingly by behavioral changes. We interpret these findings through a framework in which parenthood induces endogenous specialization in financial engagement under asymmetric time constraints and limited commitment within households. When separation risk is non-negligible and financial engagement is individual-specific, changes in personal financial behavior reallocate financial risk and control across partners in non-neutral ways. Our results identify parenthood as a central and previously underexplored driver of gender inequality in personal finances, even in a highly gender-egalitarian setting.

Using a rich and realistically calibrated life cycle model, we study the impact of access to a hybrid tenure, 'shared ownership', on individuals' optimal consumption, savings, and housing decisions. Shared ownership is a well established affordable housing tenure in the UK representing half of new affordable housing supply. It constitutes of buying a share of a home and paying subsidised rent to an institutional investor on the remainder. We find that access to shared ownership is most attractive to young, liquidity-constrained individuals who enter the housing market by buying a small share as well as old individuals who are in the process of decumulating their savings and are in turn selling shares of their home as they get older. Further, shared ownership leads to earlier housing market entry, later housing market exit, a decrease in individuals' loan-to-value ratio, and a reduction in moving activity at old age; all in comparison to a setting in which the individuals' rent-versus-own decisions are binary. Shared ownership as an additional tenure choice thus can be used as a way to enhance home ownership in areas with housing affordability constraints.

Brokerage commissions have declined substantially over recent decades worldwide. This paper studies how lower trading costs affect retail investors and the market through increased speculation. We leverage a 2017 reform in Taiwan that reduced the transaction tax specifically for day trading. Using detailed account-level transaction data, we show that even though lower trading costs mechanically benefit investors, their responses offset these gains and reduce portfolio returns. First, day trading volume increases significantly but this increase is driven disproportionately by less sophisticated investors who tend to lose money on each trade. Second, and surprisingly, day traders' gross returns per dollar traded worsen, eroding the mechanical tax-cut benefit. Consistent with the view that transaction costs serve a disciplinary role, we trace this performance deterioration to less attentive decision-making. Together, these responses result in losses concentrated among investors with smaller holdings, whereas large investors benefit. Despite individual-level losses, market quality improves: intraday liquidity increases and volatility decreases. Overall, our findings highlight a policy-relevant trade-off: increased retail speculation from lower trading costs can benefit markets while harming individual investors.