Intertemporal choice

Our fragile future under the cumulative cultural evolution of two technologies

We derive and analyse a model with unusual features characterizing human activities over the long-run. First, human population dynamics draw heavily on consumer-resource modelling in ecology in that humans must consume biological resources to produce new humans. Second, the model also draws heavily from economic growth theory in that humans do not simply consume biological resources; they also produce the resources they consume. Finally, humans use two types of technology. Consumption technology affects the rate at which humans can extract resources. Production technology controls how effectively humans convert labour into new resources. The dynamics of both types of technology are subject to cumulative cultural evolutionary processes that allow both technological progress and regress. The resulting model exhibits a wide range of dynamical regimes. That said, the system is routinely sensitive to initial conditions, with wildly different outcomes given the same parameter values. Moreover, the system exhibits a basic fragility in the sense that human activities often lead to the endogenous extinction of the human species. This can happen gently, or it can follow periods of explosive human activity with super-exponential growth that ends in collapse. This article is part of the theme issue 'Evolution and sustainability: gathering the strands for an Anthropocene synthesis'.

Self-control and unhealthy body weight: The role of impulsivity and restraint

We examine the relationship between trait self-control and body weight. Data from a population representative household survey reveal that limited self-control is strongly associated with both unhealthy body weight and poorer subjective weight-related well-being. Those with limited self-control are characterized by reduced exercising, repeated dieting, unhealthier eating habits, and poorer nutrition. We propose an empirical method to isolate two facets of self-control limitations-high impulsivity and low restraint. Each has differential predictive power. Physical activity, dieting, and overall body weight are more strongly associated with restraint; impulsivity is relatively more predictive of when, where, and what people eat.

Health & Wealth: is weight loss success related to monetary savings in U.S. adults of low-income? Findings from a National Study

BACKGROUND

Many individuals aspire to attain various goals in life, such as committing to a healthful diet to slim down or saving for retirement to enhance future welfare. While these behaviors (weight loss and saving) share the common denominator of self-regulation, it is unclear whether success in one domain is related to the other. Therefore, we examined the relationship between long term weight loss (LTWL) success and monetary savings among U.S. adults who at one point in life diverged from normal weight status.

METHODS

Data on 1994 adults with a maximum BMI ≥ 25 kg/m² and with an annual household income equal or less than 200% poverty level. Data were derived from a U.S. population-based study (NHANES). The independent variable was LTWL success (loss maintained for at least 1 year), which was operationalized as < 10% (reference group), 10.00-19.99%, and ≥ 20.00%. The dependent variable was monetary savings (e.g., 401 K), defined as a 3-category ordinal variable. We employed ordered logistic regression to estimate the relationship between LTWL success and increased odds for higher overall savings.

RESULTS

Multivariable analysis revealed that adjusting for income, education and other covariates, being in the highest LTWL category (≥20.00%) significantly reduced the likelihood of monetary savings in comparison to the reference group (OR = 0.55, 95%CI = 0.34-0.91). This relationship was not observed in the lower LTWL category (10.00-19.99%).

CONCLUSIONS

Adults who in the past were overweight or obese and who presently exhibit high levels of LTWL, were markedly less successful when it came to their finances. This might stem from significant cognitive-affective resources exerted during the weight loss process coupled with a paucity of financial resources which impede financial decision making. This supposition, however, warrants future research.

Beyond Willpower: Strategies for Reducing Failures of Self-Control

Almost everyone struggles to act in their individual and collective best interests, particularly when doing so requires forgoing a more immediately enjoyable alternative. Other than exhorting decision makers to "do the right thing," what can policymakers do to reduce overeating, undersaving, procrastination, and other self-defeating behaviors that feel good now but generate larger delayed costs? In this review, we synthesize contemporary research on approaches to reducing failures of self-control. We distinguish between self-deployed and other-deployed strategies and, in addition, between situational and cognitive intervention targets. Collectively, the evidence from both psychological science and economics recommends psychologically informed policies for reducing failures of self-control.