Great achievements in knowledge are produced by older innovators today than they were a century ago. Nobel Prize winners and great inventors have become especially unproductive at younger ages. Meanwhile, the early life cycle decline is not offset by increased productivity beyond middle age. The early life cycle dynamics are closely related to age when the PhD was received, and I discuss a theory where knowledge accumulation across generations leads innovators to seek more education over time. More generally, the narrowing innovative life cycle reduces, other things equal, aggregate creative output. This productivity drop is particularly acute if innovators' raw ability is greatest when young.

A pervasive and puzzling feature of banks’ Value-at-Risk (VaR) is its abnormally high level, which leads to excessive regulatory capital. A possible explanation for the tendency of commercial banks to overstate their VaR is that they incompletely account for the diversification effect among broad risk categories (e.g., equity, interest rate, commodity, credit spread, and foreign exchange). By underestimating the diversification effect, bank’s proprietary VaR models produce overly prudent market risk assessments. In this paper, we examine empirically the validity of this hypothesis using actual VaR data from major US commercial banks. In contrast to the VaR diversification hypothesis, we find that US banks show no sign of systematic underestimation of the diversification effect. In particular, diversification effects used by banks is very close to (and quite often larger than) our empirical diversification estimates. A direct implication of this finding is that individual VaRs for each broad risk category, just like aggregate VaRs, are biased risk assessments.

In this paper we estimate the effect of particular price incentives on consumer payment patterns using transaction-level data. We find that participation in a loyalty program and access to an interest-free period tend to increase credit card use at the expense of alternative payment methods, such as debit cards and cash. Interestingly though, the pattern of substitution from cash and debit cards differs according to the price incentive. An implication of the findings is that the Reserve Bank reforms of the Australian payments system are likely to have influenced observed payment patterns.

We study optimal taxation when consumers have temptation and self-control problems. Embedding the class of preferences developed by Gul and Pesendorfer into a standard macroeconomic setting, we first prove, in a two-period model, that the optimal policy is to subsidize savings when consumers are tempted by “excessive” impatience. The savings subsidy improves welfare because it makes succumbing to temptation less attractive. We then study an economy with a long but finite horizon which nests, as a special case, the Phelps–Pollak–Laibson multiple-selves model (thereby providing guidance on how to evaluate welfare in this model). We prove that when period utility is logarithmic, the optimal savings subsidies increase over time for any finite horizon. Moreover, as the horizon grows large, the optimal policy prescribes a constant subsidy, in contrast to the well known Chamley–Judd result.

This paper constructs a model of saving for retired single people that includes heterogeneity in medical expenses and life expectancies, and bequest motives. We estimate the model using Assets and Health Dynamics of the Oldest Old data and the method of simulated moments. Out-of-pocket medical expenses rise quickly with age and permanent income. The risk of living long and requiring expensive medical care is a key driver of saving for many higher-income elderly. Social insurance programs such as Medicaid rationalize the low asset holdings of the poorest but also benefit the rich by insuring them against high medical expenses at the ends of their lives.

Financial economics has posited a limited role for idiosyncratic noneconomic manager-specific influences, but the strategic management literature suggests such individual influences can affect corporate outcomes. We investigate whether individual managers play an economically significant role in their firms’ voluntary financial disclosure choices. Tracking managers across firms over time, we find top executives exert unique and economically significant influence (manager-specific fixed effects) on their firms’ voluntary disclosures, incremental to known economic determinants of disclosure, and firm- and time-specific effects. Managers’ unique disclosure styles are associated with observable demographic characteristics of their personal backgrounds: managers promoted from finance, accounting, and legal career tracks, managers born before World War II, and those with military experience develop disclosure styles displaying certain conservative characteristics; and managers from finance and accounting and those with military experience favor more precise disclosure styles. These plausible associations confirm that our estimated manager-specific fixed effects capture systematic long-lived differences in managers’ unique disclosure styles.

Nearly half of managers' forecasts of annual earnings per share (EPS) end in nickel intervals, whereas only about 20 percent of actual EPS end in nickel intervals. We provide evidence on the attributes, determinants, and consequences of this systematic wedge between managers' predictions and firms' ex post actual performance. Managers' nickel forecasts are not simply a benign response to uncertainty about upcoming earnings, because nickel forecasts are not only less accurate, but also they are more optimistically biased than non-nickel forecasts. In addition to uncertainty, efforts to protect the firm's proprietary information and self-serving opportunism in response to managers' economic incentives also play incremental roles in explaining managers' propensity to issue forecasts heaped at nickel intervals. We also find that managers' nickel forecasts spur even active analysts to issue forecasts heaped at nickel intervals, although analysts' forecast revisions partially adjust for the optimism and noise in managers' nickel forecasts.