To find out, the researchers controlled for various factors that might make firms more likely to invest---like size, industry, and sales---and for indicators that a place was desirable to live in, like growth in wages or population.
1.indicators n.指标,指数
为了弄明白这一问题，研究者控制了多种可能促使公司投资的因素，比如规模，产业，销售，以及一个地方适宜居住的指标，比如工资或人口的涨幅。