Utilize the input text as a context reference, choose the right relationship between Timothy Guinnane and Yale University from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

Yale University Professor Timothy Guinnane warns against making too many comparisons, partly because Germany was so much more important geopolitically than Greece today.

Answer: employer