The existence of a ‘natural rate of unemployment’ informs much of economic policy. But attempts to explain large cross-country differences and time-series changes in unemployment are unconvincing, and strong prior beliefs are required to interpret the evidence as supportive of the natural rate hypothesis. And the natural-rate hypothesis is also fragile on theoretical grounds. Stylized policy games between monetary policymakers and the private sector have suggested that discretionary policy regimes suffer from inflationary bias and that policy makers cannot achieve sustained reductions of unemployment below the natural rate. The results are radically different in the presence of labor unions, even with perfect foresight and well-defined preferences over inflation and output: a central bank that is completely indifferent to the level of inflation may obtain outcomes with high employment and zero inflation, while inflation-averse central banks generate stagflation with positive inflation and low employment. The reduced-form relation between unemployment and inflation following a shift in the central bank’s objective function can be negative or positive, depending on details.

Climate change is a time horizon problem. Economics proposes a carbon tax and leaving the rest to the market. Tax levels are calculated by combining an economic growth model with climate projections. Such models predict very little economic impact, at odds with the alarmist projections of climate science. Economic methodology and selective evidence combine to induce complacency. This was endorsed by a Nobel Prize for William Nordhaus, its leading exponent. Complacency was challenged within economics for not being predicted by extrapolation, disregarding future generations, and modelling the risks incorrectly. Economics bears some responsibility for the problem it tries to solve. It ignores non-rational forms of denial, and falls victim to them itself. With no guidance from economics on how to address climate change, the actual approach chosen is central government precommitment, in line with our own time-horizon model.

The landscape of gambling has dramatically changed. In addition to more and more jurisdictions having casinos, electronic gambling machines, lotteries and sports wagering in close proximity to individuals, online gambling has dramatically increased. Gambling has moved from being a negatively perceived activity associated with sin and vice to its current state of being viewed as a socially acceptable recreational pastime. Upwards of 80 percent of individuals report having gambled for money during their lifetime, and governments throughout the world have come to recognize that regulated forms of gambling can be a significant source of revenue. While the vast majority of individuals have no gambling-related issues, an identifiable proportion of both adults and adolescents experience significant gambling-related problems. In spite of the growing body of research which has identified many of the risk and protective factors associated with excessive problematic gambling, a limited number of prevention and treatment programs exist. This chapter examines current knowledge concerning the efficacy of existing harm minimization prevention programs and treatment of gambling disorders.