Technological Externality
A technological externality is an externality that changes another person's health, wellbeing or output directly, not through prices, as infection does.
Encyclopaedia
Explore comprehensive, evidence-informed explanations of key health economics concepts, including their development, application and relationships to other concepts. Published entries are validated through human expert review.
Concepts, entries and ontology terms
A concept page is a published entry on the wiki. Some concepts also have a full encyclopaedia article. The Health Economics Ontology (HEO) holds every concept, including dictionary terms without an article, so it is larger than the list of published pages. The knowledge graph shows how concepts relate to each other.
Theil Index Health
The Theil index in health is an entropy-based measure of relative inequality in a health outcome that splits exactly into parts between and within groups.
Theory of the Second Best
The theory of the second best is a welfare theorem that if one efficiency condition fails, as in health care, meeting the others may not raise welfare.
Threshold Price
Threshold Price is the highest price at which a health technology stays cost-effective: the price where its ICER equals the cost-effectiveness threshold.
Time Horizon
The time horizon is the period over which an economic evaluation counts costs and health effects, set long enough to capture all important differences.
Time Preference
Time preference is the preference for benefits sooner and costs later; in health economics it is one reason future costs and QALYs are discounted.
Time Trade-Off
The time trade-off (TTO) values a health state for QALYs by asking how many years in full health a person rates equal to a longer life in that state.
Time Value of Money
The time value of money is the principle that money held now is worth more than the same sum later, the reason economic evaluations discount future costs.
Time Without Symptoms of Progression
Time without symptoms of progression (TWiST) is survival free of disease symptoms and counted treatment toxicity, the reference state in Q-TWiST.
Time-Driven Activity-Based Costing
Time-driven activity-based costing (TDABC) costs health care by multiplying each resource's cost per minute of capacity by the minutes a patient uses.
Top-Down Costing
A costing approach that starts with aggregate costs and allocates them to services, activities or patients using documented shares and output counts.
Toxicity Period (TOX)
Toxicity period (TOX) is the Q-TWiST state for time with the treatment toxicity an analysis counts, often grade 3 or worse, weighted by its own utility.
Tragedy of the Commons
The tragedy of the commons is the overuse of a shared resource, such as antibiotic effectiveness, when each user keeps the gain but the cost falls on all.
Unmarketed Good
An unmarketed good is an economic good, such as health or clean air, that is not traded in markets, so no market price shows its value in appraisal.
Utility
Utility is a numerical measure of preference; in health economics, a health utility values a health state on a scale where 1 is full health and 0 is dead.
Utility Function
A utility function gives each outcome a number so that preferred outcomes score higher; in health economics it values health states, survival and income.
Utility Maximisation
Utility maximisation is the assumption that a person chooses the affordable option they rank highest, the basis of health economic models of demand.
Utility Possibility Frontier
The utility possibility frontier is a Pareto frontier of utility levels, where fixed resources such as a health budget let no one gain unless others lose.
Vaccination Externalities
Vaccination externalities are the benefits one person's vaccination gives others by cutting disease spread, benefits that person ignores when choosing.
Value Judgement
A value judgement is a normative claim about what is good or ought to be done, such as weighting all QALYs equally, which evidence alone cannot settle.