Massachusetts continues to offer the best environment among all states for science and technology development, while Mississippi offers the worst, according to the Milken Institute.

In its latest state science and technology index, the Santa Monica, Calif.-based think tank ranked Massachusetts highest for the third consecutive time in a gauge of statewide research and development activity, entrepreneurial infrastructure, investment in human capital, technology and scientific workforce, and technological outcome. The last index came out in 2004.

Maryland ranked second, followed by Colorado and California.

North Dakota, which ranked No. 45 in the previous index, moved up 14 positions to No. 31.